Issue #2471405 by tompagabor: When not logged...

Issue #2471405 by tompagabor: When not logged Drupal\Core\EventSubscriber\FinishResponseSubscriber->setExpiresNoCache() causes a PHP warning because of an invalid timezone.

core/lib/Drupal/Core/EventSubscriber/FinishResponseSubscriber.php

@@ -269,7 +269,7 @@ protected function setCacheControlNoCache(Response $response) {
    *   A response object.
    */
   protected function setExpiresNoCache(Response $response) {
-    $response->setExpires(\DateTime::createFromFormat('j-M-Y H:i:s T', '19-Nov-1978 05:00:00 GMT'));
+    $response->setExpires(\DateTime::createFromFormat('j-M-Y H:i:s T', '19-Nov-1978 05:00:00 UTC'));
   }
 
   /**