New review comment by classabbyamp on void-packages repository

https://github.com/void-linux/void-packages/pull/39984#discussion_r997532188

Comment:
```suggestion
distfiles="http://www.dhondt.de/cgx_${_cgx_ver}.all.tar.bz2"
```
and add `_cgx_ver=2.20` after `revision`

you may also want to note in a comment at the top that this needs to be synchronised with `cgx` (because same distfile)