When removing all host/service certificates via host/service-mod --certificate=, the removed certificates should be revoked, but they are not. Examine whether the --certificate option was provided to determine whether certs should be revoked, instead of looking for a cert list in the options (which in this case is empty). Fixes: https://fedorahosted.org/freeipa/ticket/6305 Reviewed-By: Jan Cholasta <jcholast@redhat.com>