Use hyphen for gerrit.skip-ensure-authenticated

git config key should consist of alphanumeric characters and '-'.
The underscore '_' is not allowed. So we're getting 'invalid key' error
when GERRIT_SKIP_ENSURE_AUTHENTICATED is set.

Let's use '-' instead of '_'.

BUG=603378

Review URL: https://codereview.chromium.org/1882833005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299952 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/tests/git_cl_test.py b/tests/git_cl_test.py
index ed24c84..a78c738 100755
--- a/tests/git_cl_test.py
+++ b/tests/git_cl_test.py
@@ -680,7 +680,7 @@
 
   @classmethod
   def _gerrit_ensure_auth_calls(cls, issue=None, skip_auth_check=False):
-    cmd = ['git', 'config', '--bool', 'gerrit.skip_ensure_authenticated']
+    cmd = ['git', 'config', '--bool', 'gerrit.skip-ensure-authenticated']
     if skip_auth_check:
       return [((cmd, ), 'true')]