Update.php in D7 is working for all users besides all true settings

Hi i have installed D7 on my website: voiceofengineers.com
Though my settings in settings.php are

$update_free_access = FALSE;

and i have gives permission for "Administer software updates " to "administrators" only. Still update.php is working for all users i.e. anonymous users as well. Check it here:

voiceofengineers/update.php

Kindly help me on how can i fix it? Is it same problem for all users?