gitc: Improve help visibility

This improves the visiblity of gitc-init if we can get the gitc config,
and hides it otherwise.

Change-Id: I82830b0b07c311e8c74397ba79eb4c361f8b6fb5

subcmds/gitc_init.py

@@ -18,10 +18,11 @@ import os
 import sys
 
 import gitc_utils
+from command import RequiresGitcCommand
 from subcmds import init
 
 
-class GitcInit(init.Init):
+class GitcInit(init.Init, RequiresGitcCommand):
   common = True
   helpSummary = "Initialize a GITC Client."
   helpUsage = """