Listen on IPv4 as well.

nginx.tpl

@@ -2,6 +2,7 @@
 server {
     server_name {{ ' '.join(service.vhosts) }};
     listen [::]:443 ssl http2;
+    listen 443 ssl http2;
 
     ssl_certificate {{ service.certificate }};
     ssl_certificate_key {{ service.certificate_key }};