drive-menu: Remove left-over signal connection

The handler itself was removed in commit 3bfaf6f88a, so the
code now fails.

Closes: https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/issues/455
Fixes: 3bfaf6f8 ("js: Use connectObject()")
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/278>

extensions/drive-menu/extension.js

@@ -39,8 +39,6 @@ class MountMenuItem extends PopupMenu.PopupBaseMenuItem {
 
         this.mount = mount;
 
-        this.connect('destroy', this._onDestroy.bind(this));
-
         let ejectIcon = new St.Icon({
             icon_name: 'media-eject-symbolic',
             style_class: 'popup-menu-icon',