Where to hook settings api init

Try it like this:

if (isset($_REQUEST['tab']) && $_REQUEST['tab']) {
    typesetter_save_settings();
}
register_sections();

$current = isset($_REQUEST['tab']) ? $_REQUEST['tab'] : 'page';

You have to check for a certain field of $_REQUEST (or $_POST etc.) before accessing it—or you get warnings.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)