Send response only if connected

application/src/main/java/org/thingsboard/server/service/edge/rpc/EdgeGrpcSession.java

@@ -253,11 +253,13 @@ public final class EdgeGrpcSession implements Closeable {
     }
 
     private void sendResponseMsg(ResponseMsg responseMsg) {
-        try {
+        if (isConnected()) {
-            responseMsgLock.lock();
+            try {
-            outputStream.onNext(responseMsg);
+                responseMsgLock.lock();
-        } finally {
+                outputStream.onNext(responseMsg);
-            responseMsgLock.unlock();
+            } finally {
+                responseMsgLock.unlock();
+            }
         }
     }