auto-install: Only run hooks once

And also silence some errors around the second run.

Change-Id: I892b0ce4ce3be43953122598de2991eb509f3d9f
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1148716
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>