Merge remote-tracking branch 'mavlink/master' into issue1185

Sync work branch.

src/VehicleSetup/SetupView.cc

@@ -120,7 +120,7 @@ void SetupView::_setConnectedView(void)
 
 void SetupView::_firmwareButtonClicked(void)
 {
-    if (_uasCurrent->isArmed()) {
+    if (_uasCurrent && _uasCurrent->isArmed()) {
         QGCMessageBox::warning("Setup", "Firmware Update cannot be performed while vehicle is armed.");
         return;
     }