Merge pull request #832 from lucky2you/gateway-rpc-resp-no-ack

BUGFIX: fixed the server do not send a PUBLIC ACK on v1/gateway/rpc

transport/mqtt/src/main/java/org/thingsboard/server/transport/mqtt/session/GatewaySessionCtx.java

@@ -155,6 +155,7 @@ public class GatewaySessionCtx {
             GatewayDeviceSessionCtx deviceSessionCtx = devices.get(deviceName);
             processor.process(new BasicTransportToDeviceSessionActorMsg(deviceSessionCtx.getDevice(),
                     new BasicAdaptorToSessionActorMsg(deviceSessionCtx, new ToDeviceRpcResponseMsg(requestId, data))));
+            ack(mqttMsg);
         } else {
             throw new JsonSyntaxException(CAN_T_PARSE_VALUE + json);
         }