he: Fixed vm absence detection
he: Fixed vm absence detection

VDSM message "Virtual machine does not exist" now includes
VM UUID, so we can't directly compare VDSM answer
with well known string anymore.
We partially fixed in https://gerrit.ovirt.org/72791
but the fix wasn't complete.

Change-Id: I7de56f44e2fe0b73bc45d2f65a70f8366ab0bf1e
Bug-Url: https://bugzilla.redhat.com/1413845
Signed-off-by: Simone Tiraboschi <cb03129c66ba4da7ba7044049d0f43907bf857bb@redhat.com>

oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha