fix JavaScript error: line 33: missing } in compound statement

from bug 53896 r=timeless, sr=shaver

xpfe/global/resources/content/htmlBindings.xml

@@ -35,6 +35,7 @@
               }
 	            break;
           }
+        }
         var controller =
           document.commandDispatcher.getControllerForCommand('cmd_scrollPageDown');
           controller.doCommand('cmd_scrollPageDown');