Stop showing "Presubmit errors, can't continue (use --no_presubmit to bypass)" when running gcl presubmit!

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/119436

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@18078 0039d316-1c4b-4281-b951-d872f2087c98