Fix document URL setting for javascript: URLs

A series of changes starting with 6440cca which removed the override
URL concept as well as intermediate cleanups such as e13762f eroded
the correctness of javascript: document URLs. Now it seems to be the
case that fixing this typo restores the correct handling for such URLs.

Addresses some concern raised in #3989.

source

@@ -83493,8 +83493,8 @@ interface <dfn>Location</dfn> { // but see also <a href="#the-location-interface
       https://software.hixie.ch/utilities/js/live-dom-viewer/?saved=2640 -> javascript:'test' in Firefox, about:blank otherwise
      -->
 
-     <li><p><span data-x="list append">Append</span> the <var>browsingContext</var>'s <span>active
-     document</span>'s <span data-x="concept-document-url">URL</span> <span
+     <li><p><span data-x="list append">Append</span> <var>browsingContext</var>'s <span>active
+     document</span>'s <span data-x="concept-document-url">URL</span> to <var>request</var>'s <span
      data-x="concept-request-url-list">URL list</span>.</p></li>
 
      <li><p>Let <var>settings</var> be <var>browsingContext</var>'s <span>active document</span>'s