chore: Fix broken active-document reference (#1063)

index.html

@@ -2354,15 +2354,15 @@ <h2>
         </p>
       </aside>
       <p>
-        If the [=application context=]'s [=active document=]'s [=Document/URL=]
-        is not [=manifest/within scope=] of the [=application context=]'s
-        [=Document/processed manifest=], the user agent SHOULD show a prominent
-        UI element indicating the [=Document/URL=] or at least its [=origin=],
-        including whether it is served over a secure connection. This UI SHOULD
-        differ from any UI used when the [=Document/URL=] is [=manifest/within
-        scope=] of the [=application context=]'s [=Document/processed
-        manifest=], in order to make it obvious that the user is navigating off
-        scope.
+        If the [=application context=]'s [=navigable/active document=]'s
+        [=Document/URL=] is not [=manifest/within scope=] of the [=application
+        context=]'s [=Document/processed manifest=], the user agent SHOULD show
+        a prominent UI element indicating the [=Document/URL=] or at least its
+        [=origin=], including whether it is served over a secure connection.
+        This UI SHOULD differ from any UI used when the [=Document/URL=] is
+        [=manifest/within scope=] of the [=application context=]'s
+        [=Document/processed manifest=], in order to make it obvious that the
+        user is navigating off scope.
       </p>
       <aside class="note">
         <p>