Don't re-produce the same SD again.

Change-Id: I7f5c267c8afa961bd5cde5e2b67d598a1fb5e486
Signed-off-by: Eduardo <ewarszaw@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/18201
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Maor Lipchuk <mlipchuk@redhat.com>