Save settings after changing controller keybind

The game automatically writes settings to disk after any other setting
is changed, so it should do the same whenever the user changes
controller keybinds.

desktop_version/src/Input.cpp

@@ -1840,6 +1840,7 @@ void titleinput(void)
                 key.controllerButtonDown()      )
         {
             updatebuttonmappings(game.currentmenuoption);
+            game.savestatsandsettings_menu();
         }
 
     }