Privacy of uploaded file not honered + solution [Integrated]

I check the radiobutton /users/configure.php ->tab 'submission', Files: "Files can be modified only by their original authors, plus associates and editors."

$context['users_without_file_overloads']='R'; is set in /parameters/users.include.php

Reloading configure.php again, the checkbox appeared to have not been set.

I believe the problem can be found after line 496 in /users/configure.php, where the value is set to R instead of Y:

    // control of file overload
    $label = i18n::s('Files');
    $input = '<input type="radio" name="users_without_file_overloads" value="N"';
    if(!isset($context['users_without_file_overloads']) || ($context['users_without_file_overloads'] != 'Y'))
        $input .= ' checked="checked"';
    $input .= '/> '.i18n::s('Any member can update files posted by others.');
    $input .= BR.'<input type="radio" name="users_without_file_overloads" value="R"';
    if(isset($context['users_without_file_overloads']) && ($context['users_without_file_overloads'] == 'Y'))
        $input .= ' checked="checked"';
    $input .= '/> '.i18n::s('Files can be modified only by their original authors, plus associates and editors.');
    $fields[] = array($label, $input);