window-list: Init translations

Whoops, we are missing the bindtextdomain() call, which means translations
won't work when no other extension that shares the same domain is used
(like in GNOME Classic for instance).

https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/issues/340
(cherry picked from commit c9d7f99d50f96d29c38380d9f0e3c9ddc660db9f)

extensions/window-list/extension.js

@@ -1105,6 +1105,8 @@ class WindowList extends St.Widget {
 
 class Extension {
     constructor() {
+        ExtensionUtils.initTranslations();
+
         this._windowLists = null;
         this._hideOverviewOrig = Main.overview.hide;
     }