Restart lighttpd on host running certbot to reload updated certificates

[serhepopovych]

We currently run certbotsh-publish from deploy_hook that puts PKCS#12 file to lighttpd served directory from where
remote clients will fetch this file using curl/wget from certbotsh-update.

However on certbot host itself (acme-le) there is no action that trigger lighttpd restart. Thus on it's letsencrypt
certificate expire remote clients not able to fetch their certificates anymore.

We need to trigger lighttpd service restart on new certificate deploy on certbot host.