Bot_update takes care of running gclient sync after apply_issue, so this is
unnecessary.

BUG=

Review URL: https://codereview.chromium.org/242433002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@265031 0039d316-1c4b-4281-b951-d872f2087c98