New comment by xtraeme on void-packages repository

https://github.com/void-linux/void-packages/pull/12797#issuecomment-508975335
Comment:
Also added a check to verify that all dependencies exist:

```
[juan@leysa void-packages]$ ./xbps-src -Nt install autofs
=> autofs-5.1.5_3: building [gnu-configure] ...
=> ERROR: autofs-5.1.5_3: host dependency 'rpcgen' does not exist!
[juan@leysa void-packages]$
```