kra-install: better warning message
User would like to see CA installation command in KRA installation
warning message.
This makes warning message similar to other installer messages where it
does suggests a command to run.
https://pagure.io/freeipa/issue/6952
Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
Reviewed-By: Felipe Barreto <fbarreto@redhat.com>