[Samba] Building on RHEL 8

[Nico Kadel-Garcia]

> Mock can't resolve the confusion for RHEL 8, which may be fixable with
> mock updates, but right now my use of "mock" for Samba is blocked.

The workaround is to change the "mock" configuration to use "best=0".
The new "module" RPMs lead to confusion for dnf and mock. I really
don't like them, at all, but they turn out to provide critical
dependencies.

My hooks to build Samba 4.10.3 via RPMs on RHEL 7, 8, and various
fedora releases with the domain controller fully enabled are published
at https://github.com/nkadel/sambarepo. They rely on a local
"reposync" of RHEL 8 channels, and on Troy Dawson's rhelbeta packages,
as described in the README.md. I look forward to testing CentOS 8 as
soon as it is first published.

Nico Kadel-Garcia <nkadel at gmail.com>