ClusterService - pushNotificationToTransport - fire callback.onSuccess(null) if serviceId is empty

@@ -198,6 +198,9 @@ public class DefaultTbClusterService implements TbClusterService {
     public void pushNotificationToTransport(String serviceId, ToTransportMsg response, TbQueueCallback callback) {
         if (serviceId == null || serviceId.isEmpty()){
             log.trace("pushNotificationToTransport: skipping message without serviceId [{}], (ToTransportMsg) response [{}]", serviceId, response);
+            if (callback != null) {
+                callback.onSuccess(null); //callback that message already sent, no useful payload expected
+            }
             return;
         }
         TopicPartitionInfo tpi = partitionService.getNotificationsTopic(ServiceType.TB_TRANSPORT, serviceId);