add logic to remove the plugins folder when the version changed

Change-Id: Idb0ac34376c4eed81bf37da7afe670d9d9a42457

src/slic3r/GUI/GUI_App.hpp

@@ -526,6 +526,7 @@ private:
     bool            on_init_network(bool try_backup = false);
     void            init_networking_callbacks();
     void            init_app_config();
+    void            remove_old_networking_plugins();
     //BBS set extra header for http request
     std::map<std::string, std::string> get_extra_header();
     void            init_http_extra_header();