This script modifies the config file at /private/etc/apache2/httpd.conf which is for the copy of Apache that ships with OS X.

If you install Apache with homebrew the config file is located at /usr/local/etc/apache2/2.4/httpd.conf

Maybe you could update the script to modify both files?

Why use homebrew Apache:

The latest macOS 10.12 Sierra comes with Apache 2.4 pre-installed, however, it is no longer a simple task to use this version with Homebrew because Apple has removed some required scripts in this release. However, the solution is to install Apache 2.4 via Homebrew and then configure it to run on the standard ports (80/443).
https://getgrav.org/blog/macos-sierra-apache-multiple-php-versions