Bug 1891644 - Fix for test_moz_page_nav.html high frequency failure r=reusable-components-reviewers,tgiles

Differential Revision: https://phabricator.services.mozilla.com/D207589

toolkit/content/tests/widgets/test_moz_page_nav.html

@@ -242,12 +242,12 @@ function isActiveElement(expectedActiveEl) {
     )
     await tab();
     ok(
-      isActiveElement(supportLink),
+      isActiveElement(supportLink.linkEl),
       "The support link is selected"
     )
     await tab();
     ok(
-      isActiveElement(externalLink),
+      isActiveElement(externalLink.linkEl),
       "The external link is selected"
     )
     await tab(true);