Hide lang and theme select from login page

I use my NOCC installation alone and don't need the language and theme selection at the login page. But I still want the possibility to change language and theme from the preference page (which I use). So I added the following preference to the config file:

// hide the language selection from the login page
$conf->hide_lang_select_from_login_page = true;

// hide the theme selection from the login page
$conf->hide_theme_select_from_login_page = false;

Greetings,
Tim Gerundt