added final change

lib/Utils.js

@@ -244,7 +244,7 @@ function _getFavicon(faviconURL) {
   xhr.mozBackgroundRequest = true;
   xhr.onload = function() {
     if (this.status == 401 || this.status == 404) {
-      faviconPromise.resolve("");
+      unresolved();
     } else {
       faviconPromise.resolve(faviconURL);
     }