Don't be pedantic about .gclient file for non-mutating commands.

This is primarily a hack to enable the chromeos ebuild.

BUG=367027
TBR=iannucci@chromium.org,mmoss@chromium.org

Review URL: https://codereview.chromium.org/490233003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@291075 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/gclient.py b/gclient.py
index 3e35ebd..94a981d 100755
--- a/gclient.py
+++ b/gclient.py
@@ -1324,12 +1324,11 @@
     if not self.dependencies:
       raise gclient_utils.Error('No solution specified')
 
-    self._CheckConfig()
-
     revision_overrides = {}
     # It's unnecessary to check for revision overrides for 'recurse'.
     # Save a few seconds by not calling _EnforceRevisions() in that case.
     if command not in ('diff', 'recurse', 'runhooks', 'status'):
+      self._CheckConfig()
       revision_overrides = self._EnforceRevisions()
     pm = None
     # Disable progress for non-tty stdout.