Fixed migration job to use the new get_by_id method on db

            raise JobCancelError('author have no right to migrate to this hv')

        # Update the VM object:

        try:

            self.manager.server.objects.update(ids=(vm_id,))

            vm = self.manager.server.objects.get_by_id(vm_id)

        except UnknownObjectError:

        vm = self.manager.server.db.get_by_id(vm_id)

        if vm is None:

            raise JobCancelError('Source VM not found')

        # Get the source and destination hv clients: