amavisd and centos8 compatibility

[Ralph Seichter]

* support at mmarzouki.de:

> tools like unrar or cabextract is not available in centos8 with
> epel-release and enabled PowerTools.

Amavis searches the system it is running on for some well-known
binaries. If CentOS uses different ones, you can manually change the
list of binaries by modifying your amavisd.conf. Also, if you don't
expect to receive .zoo or .cab archives, not having extractor utilities
for them won't hurt much.

What tools are available on a particular platform is not an Amavis
issue, so I suggest you contact the CentOS package maintainers.

-Ralph