Remove white-space in user_guide/configuration

Commit removes white-space in user_guide/configuration in example for
tsd.storage.hbase.zk_quorum, because it's no white-space in real-life OTSDB
configuration. Therefore, it's confusing to show one in documentation.

Signed-off-by: Zdenek Styblik <stybla@turnovfree.net>
Merge pull request #41 from zstyblik/fix-wspace-in-userguide-config

Remove white-space in user_guide/configuration