Replace usage of old-style WHATWG spec links

components/script/dom/webidls/HTMLPreElement.webidl

@@ -3,12 +3,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-// https://www.whatwg.org/html/#htmlpreelement
+// https://html.spec.whatwg.org/multipage#htmlpreelement
 interface HTMLPreElement : HTMLElement {
   // also has obsolete members
 };
 
-// https://www.whatwg.org/html/#HTMLPreElement-partial
+// https://html.spec.whatwg.org/multipage#HTMLPreElement-partial
 partial interface HTMLPreElement {
   //         attribute long width;
 };