Change default settings for permit/deny in device options

Default settings for permit/deny in device options are 0.0.0.0/0.0.0.0.
I would like to change default to something else.
Where do I do this?
I know these settings are in /var/www/html/admin/modules/core/functions.inc.php under $tmparr['permit']. I assume if I changed that I would get "tampered file" warnings. Any place to change this in FreePBX?

Thanks.

FreePBX12, Asterisk 11