do stuff only for DataPoints who have a register

src/main/java/ch/hevs/isi/field/FieldConnector.java

@@ -95,6 +95,8 @@ public class FieldConnector implements DataPointListener {
     @Override
     public void onNewValue(DataPoint dp) {
         ModbusRegister mR = ModbusRegister.getRegisterFromDatapoint(dp);    //search the corresponding register to the datapoint
+        if(mR == null) return; //if the register is not found, return
+
         if(dp.isOutput()){  //write only on the datapoints, which are outputs
             if(dp.getLabel().equals("REMOTE_SOLAR_SW")      //write only boolean outputs
                 ||dp.getLabel().equals("REMOTE_WIND_SW")