New comment by Chocimier on void-packages repository

https://github.com/void-linux/void-packages/pull/21746#issuecomment-625900383

Comment:
Nice.

Per [spec](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html#variables) it should be rather `${XDG_CONFIG_HOME:-$HOME/.config}/xbps-src.conf` to not read .config when `XDG_` is set.