Fix Domain not found exception handling.

                # sometimes, libvirt tells us too late when a domain is removed

                # we just ignore the error and remove the domain

                dom.hypervisor.domains.pop(dom.name)

                dom.tag_db.remove_sub_object(dom.name)

                dom.hypervisor.handler.tag_db.remove_sub_object(dom.name)

                return

            logger.exception('Unexpected libvirt error')

            dom.hypervisor.handler.virt_connect_restart()