DNSSEC: prevent ipa-ods-exporter from looping after service auto-restart
    
    It might happen that systemd will restart the service even if there is
    no incomming connection to service socket. In that case we want to exit
    because HSM synchronization is done before socket.accept() and we want
    to synchronize HSM and DNS zones at the same time.
    
    https://fedorahosted.org/freeipa/ticket/5273
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>
    Reviewed-By: Oleg Fayans <ofayans@redhat.com>