New comment by unspecd on void-packages repository

https://github.com/void-linux/void-packages/pull/29646#issuecomment-803518473

Comment:
The ppp configuration script uses `/usr/local` as prefix, so we need to override it.
```sh
#!/bin/sh
# Where to install stuff by default
DESTDIR=/usr/local
SYSCONF=/etc
…
    case $arg in
	--prefix)	 DESTDIR=$val ;;
```