Error if $_SERVER['HTTP_REFERER'] not present

[Robin Sallis]

In some situations $_SERVER['HTTP_REFERER'] may not be present (e.g. referrer is disabled), which causes a PHP notice and failed redirect.

Suggest a change here:

if(isset($_SERVER['HTTP_REFERER'])) {
    $this->session->redirect($_SERVER['HTTP_REFERER']);
    $this->halt();
}

[Roland Toth Pal]

Thanks, I will include in 1.9.4.

[Robin Sallis]

Thanks for the update.