[HttpFoundation] Officialize the 308 redirect RFC

Author: fabpot

Response.php

@@ -83,7 +83,7 @@ class Response
         305 => 'Use Proxy',
         306 => 'Reserved',
         307 => 'Temporary Redirect',
-        308 => 'Permanent Redirect',    // RFC-reschke-http-status-308-07
+        308 => 'Permanent Redirect',    // RFC7238
         400 => 'Bad Request',
         401 => 'Unauthorized',
         402 => 'Payment Required',