Fixed a bug

Author: fabihaahmed

notebook/static/notebook/js/notebook.js

@@ -1212,7 +1212,7 @@ define([
         // This will put all the deleted cells back in one location, rather than
         // where they came from. It will do until we have proper undo support.
         undelete_backup.index = cursor_ix_after;
-        $('#undelete_cell').removeClass('disabled').removeAttr("aria-label");
+        $('#undelete_cell').removeClass('disabled');
 
         this.undelete_backup_stack.push(undelete_backup);
         this.set_dirty(true);
@@ -1617,13 +1617,13 @@ define([
         if (!this.paste_enabled) {
             $('#paste_cell_replace').removeClass('disabled')
                 .on('click', function () {that.keyboard_manager.actions.call(
-                    'jupyter-notebook:paste-cell-replace');}).removeAttr("aria-label");
+                    'jupyter-notebook:paste-cell-replace');});
             $('#paste_cell_above').removeClass('disabled')
                 .on('click', function () {that.keyboard_manager.actions.call(
-                    'jupyter-notebook:paste-cell-above');}).removeAttr("aria-label");
+                    'jupyter-notebook:paste-cell-above');});
             $('#paste_cell_below').removeClass('disabled')
                 .on('click', function () {that.keyboard_manager.actions.call(
-                    'jupyter-notebook:paste-cell-below');}).removeAttr("aria-label");
+                    'jupyter-notebook:paste-cell-below');});
             this.paste_enabled = true;
         }
     };
@@ -1933,7 +1933,7 @@ define([
      */
     Notebook.prototype.enable_attachments_paste = function () {
         if (!this.paste_attachments_enabled) {
-            $('#paste_cell_attachments').removeClass('disabled').removeAttr("aria-label");
+            $('#paste_cell_attachments').removeClass('disabled');
             this.paste_attachments_enabled = true;
         }
     };
@@ -1943,7 +1943,7 @@ define([
      */
     Notebook.prototype.set_insert_image_enabled = function(enabled) {
         if (enabled) {
-            $('#insert_image').removeClass('disabled').removeAttr("aria-label");
+            $('#insert_image').removeClass('disabled');
         } else {
             $('#insert_image').addClass('disabled');
         }