Joystick can't be enabled if no joysticks connected

src/Joystick/JoystickManager.h

@@ -20,8 +20,6 @@
 
 Q_DECLARE_LOGGING_CATEGORY(JoystickManagerLog)
 
-class QGCApplicaiton;
-
 class JoystickManager : public QGCTool
 {
     Q_OBJECT

src/Vehicle/Vehicle.cc

@@ -1057,7 +1057,10 @@ void Vehicle::_loadSettings(void)
         _joystickMode = JoystickModeRC;
     }
 
-    _joystickEnabled = settings.value(_joystickEnabledSettingsKey, false).toBool();
+    // Joystick enabled is a global setting so first make sure there are any joysticks connected
+    if (qgcApp()->toolbox()->joystickManager()->joysticks().count()) {
+        _joystickEnabled = settings.value(_joystickEnabledSettingsKey, false).toBool();
+    }
 }
 
 void Vehicle::_saveSettings(void)