No externpasscheck option in FreePBX

Asterisk has a built in feature called externpasscheck which is supposed to go in the voicemail.conf file. There is an included script with Asterisk /usr/src/contrib/scipts/voicemailpwcheck.py that checks the passwords users enter and prevents them from using weak passwords. To enable it you're supposed to just set externpasscheck=(script location) in voicemail.conf but our voicemail.conf file says it's auto-generated and both of the includes (vm_email.inc and vm_general.inc) say they're auto-generated.

The FreePBX Voicemail Admin page does not have a text box for entering a value for 'externpasscheck'

This page has more info on the feature: http://www.asteriskdocs.org/en/3rd_Edition/asterisk-book-html-chunk/Voicemail_id263499.html