Fix static tests

Author: nmalevanec

app/code/Magento/PageCache/view/frontend/web/js/page-cache.js

@@ -64,7 +64,7 @@ define([
             contents = function (elem) {
                 return $.map(elem, function (el) {
                     try {
-                        return $.nodeName(el, "iframe") ?
+                        return $.nodeName(el, 'iframe') ?
                             el.contentDocument || (el.contentWindow ? el.contentWindow.document : []) :
                             $.merge([], el.childNodes);
                     } catch (e) {