Bug 58786 No text shown when all panels deleted

patch by jon@rekai.net r=doron sr=neil

xpfe/components/sidebar/resources/sidebarOverlay.js

@@ -486,7 +486,6 @@ function (force_reload)
       this.node.removeAttribute('hidden');
   } else {
       no_panels_iframe.removeAttribute('hidden');
-      this.node.setAttribute('hidden','true');
   }
 
   this.initialized = true;