revert consul naming service

[chenBright]

What problem does this PR solve?

Issue Number: #2123

Problem Summary:
ConsulNamingService其实不是PeriodicNamingService，不是简单的轮询，而是长轮询，每次rpc成功后，立即发起下一次长轮询。只有失败了，才会sleep。
Blocking Queries：

Many endpoints in Consul support a feature known as "blocking queries". A blocking query is used to wait for a potential change using long polling.

What is changed and the side effects?

Changed:
回退#2123 ConsulNamingService的改动

Side effects:

• Performance effects(性能影响):

• Breaking backward compatibility(向后兼容性):

---

Check List:

• Please make sure your changes are compilable(请确保你的更改可以通过编译).
• When providing us with a new feature, it is best to add related tests(如果你向我们增加一个新的功能, 请添加相关测试).
• Please follow Contributor Covenant Code of Conduct.(请遵循贡献者准则).

[wwbmmm]

CI重试之后还是失败，看起来和代码改动无关

[wwbmmm]

master修复了CI失败，可以rebase一下

[chenBright]

CI是不是还有问题？我本地跑是可以过的，但是CI跑了几次，都是core在这个地方。

[ RUN ] NamingServiceTest.consul_with_backup_file
temp_file_e34bq7
Segmentation fault (core dumped)
corefile=./core.brpc_naming_ser.12853 prog=brpc_naming_service_unittest
./run_tests.sh: 42: gdb: not found

[wwbmmm]

CI是不是还有问题？我本地跑是可以过的，但是CI跑了几次，都是core在这个地方。

[ RUN ] NamingServiceTest.consul_with_backup_file
temp_file_e34bq7
Segmentation fault (core dumped)
corefile=./core.brpc_naming_ser.12853 prog=brpc_naming_service_unittest
./run_tests.sh: 42: gdb: not found

看上去似乎和改动有关

[chenBright]

CI是不是还有问题？我本地跑是可以过的，但是CI跑了几次，都是core在这个地方。

[ RUN ] NamingServiceTest.consul_with_backup_file
temp_file_e34bq7
Segmentation fault (core dumped)
corefile=./core.brpc_naming_ser.12853 prog=brpc_naming_service_unittest
./run_tests.sh: 42: gdb: not found

看上去似乎和改动有关

是的，现在好了。git commit不太整洁，合的时候需要square一下。