Prevent from deleting refs/changes/

Everything under refs/changes/ should be protected by Gerrit, users
shouldn't be able to delete particular patch set or whole change from
review process.

Change-Id: Ia318fed10030583a1e416245ad0ef1e457ed083f
Signed-off-by: Dariusz Luksza <dariusz@luksza.org>
1 file changed