bug fix.

Author: m4gr3d

ServiceApp/src/org/droidplanner/services/android/core/drone/autopilot/generic/GenericMavLinkDrone.java

@@ -172,8 +172,6 @@ public MagnetometerCalibrationImpl getMagnetometerCalibration() {
 
     @Override
     public void destroy(){
-        events.removeAllDroneListeners();
-
         ParameterManager parameterManager = getParameterManager();
         if (parameterManager != null)
             parameterManager.setParameterListener(null);