Avoid using REQUEST_URI for redirection

* Stick with PMA_sendHeaderLocation to handle server weirdness
* Use already calculated URL

Signed-off-by: Michal Čihař <michal@cihar.com>

libraries/config/PageSettings.php

@@ -112,7 +112,10 @@ class PageSettings
             $result = PMA_saveUserprefs($cf->getConfigArray());
             if ($result === true) {
                 // reload page
-                header('Location: ' . $_SERVER['REQUEST_URI']);
+                $response = Response::getInstance();
+                PMA_sendHeaderLocation(
+                    $response->getFooter()->getSelfUrl('unencoded')
+                )
                 exit();
             } else {
                 $error = $result;