Bug 1508080 - Don't set directionality on identity-icon-labels on extension pages r=dao

Differential Revision: https://phabricator.services.mozilla.com/D42000

--HG--
extra : moz-landing-system : lando

browser/base/content/browser-siteIdentity.js

@@ -770,6 +770,7 @@ var gIdentityHandler = {
         "identity.extension.label",
         [extensionName]
       );
+      icon_labels_dir = "";
     } else if (this._uriHasHost && this._isSecureConnection) {
       // This is a secure connection.
       this._identityBox.className = "verifiedDomain";