add ssl_session_tickets to default site

Fixes #580

nginx.tmpl

@@ -70,6 +70,7 @@ server {
 	access_log /var/log/nginx/access.log vhost;
 	return 503;
 
+	ssl_session_tickets off;
 	ssl_certificate /etc/nginx/certs/default.crt;
 	ssl_certificate_key /etc/nginx/certs/default.key;
 }