Remove another comment

(I won't implement that check because I consider that an edge case, which
isn't worth a lot of effort.)

Author: pabzm

program/js/app.js

@@ -7781,7 +7781,6 @@ function rcube_webmail() {
     };
 
     // TODO: In the receive callback, can we wait for the confirmation dialog without introducing async/await and Promises?
-    // TODO: save only if the list is different than at start
     this.make_folder_lists_sortable = () => {
         const mainFolderList = this.gui_objects.subscriptionlist;
         $folderLists = $('ul', mainFolderList.parentElement);