Only do requestFocus when going full screen.

src/control_ui.cpp

@@ -96,7 +96,6 @@ void ControlUI::full_screen(bool do_it) {
     $controller.requestFocus();
   } else {
     $presenter.setSize({$window_size.x/2, $window_size.y/2});
-    $controller.requestFocus();
   }
 
   $full_screen = do_it;