Make the built-in wiitdb files optional

There are some cases where overriding the opening.bnr names
isn't desirable, such as when someone has several modded
versions of a game that differ in names but not game IDs.

Source/Core/DolphinQt2/Settings/InterfacePane.h

@@ -36,6 +36,7 @@ private:
   QCheckBox* m_checkbox_use_panic_handlers;
   QCheckBox* m_checkbox_enable_osd;
   QCheckBox* m_checkbox_show_active_title;
+  QCheckBox* m_checkbox_use_builtin_title_database;
   QCheckBox* m_checkbox_pause_on_focus_lost;
   QCheckBox* m_checkbox_hide_mouse;
 };