Enable undo history after loading initial file and fix pterodactyl#1159 (pterodactyl#1180)

Author: lancepioch

resources/themes/pterodactyl/server/files/edit.blade.php

@@ -52,6 +52,7 @@
     <script>
         $(document).ready(function () {
             Editor.setValue($('#editorSetContent').val(), -1);
+            Editor.getSession().setUndoManager(new ace.UndoManager());
             $('#editorLoadingOverlay').hide();
         });
     </script>