rhn: add try/except around sam check

rhbz#913579
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=913579

Change-Id: Ic2ed5c498cacebe7ea861cea10332ad1c485e3c5
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>
RHEV-H ONLY: correct boot menu options due to livecd-tools update

rhbz#868762
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=975291
Change-Id: I4dca4fea201743f429ee384b1bd251dbd6a398d8
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>