Updated libvirt perl bindings to go along with libvirt changes
in req#860506.

- Update suse-set-migration-constraints.patch
Remove code which handled --max_factor. The total amount of
transferred data is no indicator to trigger the final stop+copy.
This should have been removed during upgrade to Xen 4.7.
Reduce default value of --max_iters from 5 to 2.
The workload within domU will continue to produce dirty pages.
It is unreasonable to expect any slowdown during migration.
Now there is one initial copy of all memory, one instead of four
iteration for dirty memory, and a final copy iteration prior move.