Server Roles: provide an API for setting CA renewal master
`ipa config-mod` gained '--ca-renewal-master' options which can be used to
set CA renewal master to a different server. Obviously, this server has to
have CA role enabled.
Reviewed-By: Jan Cholasta <email@example.com>
Reviewed-By: Martin Basti <firstname.lastname@example.org>
Reviewed-By: Pavel Vomacka <email@example.com>