packaging: setup: disable yum transaction rollback if no rollback is available

rhel yum does not downgrade on rollback but erase and install, this
cause packages that cannot be rollbacked to be actually erased.

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1002804
Change-Id: Ie3f868a84453e6e58de173e57a280fc51b5e9dd1
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>