refs #6445 - purge configuration which is no longer needed.

After running, ```foreman-installer --foreman-ipa-authentication=true```, content in ```/etc/httpd/conf.d/05-foreman-ssl.d``` gets populated. When then rerunning the installer with ```--foreman-ipa-authentication=false```, the execution fails because httpd cannot be restarted because config files in that directory use directives supported by modules that are no longer loaded. This will purge those extra files.