removed hdfs schema from constructor string

[rporres]

hdfs client fails to get built otherwise

# cat /siva.txt | pga get -i -o hdfs://hdfs-namenode-0.hdfs-namenode.default.svc.cluster.local:8020/repositories
Error: could not create HDFS client: no available namenodes: dial tcp: address hdfs://hdfs-namenode-0.hdfs-namenode.default.svc.cluster.local:8020/repositories: too many colons in address
Usage:
  pga get [flags]

Flags:
  -h, --help               help for get
  -j, --jobs int           number of concurrent gets allowed (default 10)
  -l, --lang stringSlice   list of languages that the repositories should have
  -o, --output string      path where the siva files should be stored (default ".")
  -i, --stdin              take list of siva files from standard input
  -u, --url string         regular expression that repo urls need to match

Global Flags:
  -v, --verbose   log more information

could not create HDFS client: no available namenodes: dial tcp: address hdfs://hdfs-namenode-0.hdfs-namenode.default.svc.cluster.local:8020/repositories: too many colons in address