removed erroneous trailing xml comment r=jminta

calendar/sunbird/base/content/hiddenWindow.xul

@@ -61,7 +61,7 @@
   <toolbox id="calendar-toolbox" class="toolbox-top">
     <toolbar type="menubar" id="main-menubar" class="chromeclass-menubar"
              customizable="true" defaultset="menubar-items"
-             mode="icons" iconsize="small">--> <!-- context="toolbar-context-menu"> -->
+             mode="icons" iconsize="small"> <!-- context="toolbar-context-menu"> -->
       <toolbaritem id="menubar-items" align="center">
 <!-- The entire main menubar is placed into calendar-menubar.inc, so that it can be shared by
      hiddenWindow.xul. -->