Prompt for forwarder in dnsforwardzone-add
When the command ipa dnsforwardzone-add is invoked without
specifying the forwarder as an argument and the forward
policy is not set to none, prompt for DNS forwarder.
https://fedorahosted.org/freeipa/ticket/6169
Reviewed-By: Petr Spacek <pspacek@redhat.com>