[NEW] cluster模式下增加对ipv6地址的支持

[beihai23]

当迁移任务涉及的redis集群使用ipv6地址时，redis-shake无法建立连接。日志如下：

2022-09-13 08:37:54 INF GOOS: linux, GOARCH: amd64                                                                                                                                                                                                                                                                                                                                 2022-09-13 08:37:54 INF Ncpu: 4, GOMAXPROCS: 4                                                                                                                                                                                                                                                                                                                                     2022-09-13 08:37:54 INF pid: 402                                                                                                                                                                                                                                                                                                                                                   2022-09-13 08:37:54 INF pprof_port: 0                                                                                                                                                                                                                                                                                                                                              2022-09-13 08:37:54 INF No lua file specified, will not filter any cmd.                                                                                                                                                                                                                                                                                                            2022-09-13 08:37:54 PNC dial tcp: address 2002:ac1f:89cc:1::a099:6379: too many colons in address                                                                                                                                                                                                                                                                                  panic: dial tcp: address 2002:ac1f:89cc:1::a099:6379: too many colons in address                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      goroutine 1 [running]:                                                                                                                                                                                                                                                                                                                                                             github.com/rs/zerolog.(*Logger).Panic.func1(0xc00001a910, 0x49)                                                                                                                                                                                                                                                                                                                            github.com/rs/zerolog@v1.27.0/log.go:359 +0x4f                                                                                                                                                                                                                                                                                                                             github.com/rs/zerolog.(*Event).msg(0xc0000c49c0, 0xc00001a910, 0x49)                                                                                                                                                                                                                                                                                                                       github.com/rs/zerolog@v1.27.0/event.go:156 +0x30c                                                                                                                                                                                                                                                                                                                          github.com/rs/zerolog.(*Event).Msg(...)                                                                                                                                                                                                                                                                                                                                                    github.com/rs/zerolog@v1.27.0/event.go:108                                                                                                                                                                                                                                                                                                                                 github.com/alibaba/RedisShake/internal/log.logFinally(0xc0000c49c0, 0xc00001a8c0, 0x49, 0x0, 0x0, 0x0)                                                                                                                                                                                                                                                                                     github.com/alibaba/RedisShake/internal/log/func.go:71 +0x85                                                                                                                                                                                                                                                                                                                github.com/alibaba/RedisShake/internal/log.Panicf(0xc00001a8c0, 0x49, 0x0, 0x0, 0x0)                                                                                                                                                                                                                                                                                                       github.com/alibaba/RedisShake/internal/log/func.go:27 +0x6d                                                                                                                                                                                                                                                                                                                github.com/alibaba/RedisShake/internal/log.PanicError(0x890f40, 0xc0000ce640)                                                                                                                                                                                                                                                                                                              github.com/alibaba/RedisShake/internal/log/func.go:31 +0x5a                                                                                                                                                                                                                                                                                                                github.com/alibaba/RedisShake/internal/client.NewRedisClient(0xc00001e6a0, 0x1b, 0x0, 0x0, 0xc000024f70, 0x10, 0x203000, 0x54dd1b)                                                                                                                                                                                                                                                         github.com/alibaba/RedisShake/internal/client/redis.go:31 +0x987                                                                                                                                                                                                                                                                                                           github.com/alibaba/RedisShake/internal/writer.(*RedisClusterWriter).loadClusterNodes(0xc000200000, 0xc00001e6a0, 0x1b, 0x0, 0x0, 0xc000024f70, 0x10, 0x0)                                                                                                                                                                                                                                  github.com/alibaba/RedisShake/internal/writer/redis_cluster.go:29 +0x91                                                                                                                                                                                                                                                                                                    github.com/alibaba/RedisShake/internal/writer.NewRedisClusterWriter(0xc00001e6a0, 0x1b, 0x0, 0x0, 0xc000024f70, 0x10, 0x0, 0xc0000c4000, 0x70)                                                                                                                                                                                                                                             github.com/alibaba/RedisShake/internal/writer/redis_cluster.go:22 +0x95                                                                                                                                                                                                                                                                                                    main.main()                                                                                                                                                                                                                                                                                                                                                                                github.com/alibaba/RedisShake/cmd/redis-shake/main.go:59 +0x891   

需要在建立连接之前对ipv6地址进行处理，用[]括进来就可以了。