socketclient heartbeat

lib/im/SocketClient.dart

@@ -54,11 +54,11 @@ class SocketClient {
   }
 
   heartbeat() {
-    Timer.periodic(const Duration(milliseconds: 3000), (timer) {
+    Timer.periodic(const Duration(milliseconds: 30000), (timer) {
       debugPrint("heartbeat: ${DateTime.now().millisecondsSinceEpoch}");
       Uint8List data = utf8.encode(jsonEncode({"heartbeat": DateTime.now().millisecondsSinceEpoch}));
-      MsgData msgData = MsgData(to: "0", from: userId, type: MsgType.TEXT, data: data);
-      final proto2 = Proto(5, 1, msgData.writeToBuffer());
+      MsgData msgData = MsgData(from: userId, type: MsgType.TEXT, data: data);
+      final proto2 = Proto(3, 1, msgData.writeToBuffer());
       _socket.add(proto2.toBytes());
     });
   }