packaging: spec: /var/lib/ovirt-engine/backups does not need to be owned by ovirt

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1007751
Change-Id: I9ec6806b17e70b9e5bf9b2f29a3504737a6be0a3
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>