Save currently active receiver and restore on reboot (#1091)

* save active receiver and restore on reboot

Co-authored-by: Kern, Thomas <thomas@kernwelt.de>

main/ZgatewayRF.ino

@@ -292,7 +292,7 @@ void MQTTtoRF(char* topicOri, JsonObject& RFdata) { // json object decoding
         Log.error(F("MQTTtoRF Fail json" CR));
       }
     }
-    enableActiveReceiver();
+    enableActiveReceiver(false);
   }
 }
 #  endif