ISOProperties: Don't block when opening default INI in text editor

The purpose of blocking is to reload user INIs after they
have been edited. However, ISOProperties never reloads
default INIs, because they aren't meant to be edited.
Blocking on default INIs is thus useless, and it's
rather annoying for games that have two default INIs,
because it makes it impossible to see both at once.

Source/Core/DolphinWX/ISOProperties.h

@@ -195,7 +195,7 @@ private:
 		IDM_BNRSAVEAS
 	};
 
-	void LaunchExternalEditor(const std::string& filename);
+	void LaunchExternalEditor(const std::string& filename, bool wait_until_closed);
 
 	void CreateGUIControls(bool);
 	void OnClose(wxCloseEvent& event);