Don't rely on the freaky tryserver.py script anymore. Use gcl codereview settings instead.

TEST=gcl try still works, shouldn't break git-try
BUG=none

Review URL: http://codereview.chromium.org/123020

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@18198 0039d316-1c4b-4281-b951-d872f2087c98