Switch to http2 directive in nginx configs

2024/06/02 11:05:53 [warn] 30324#30324: the "listen ... http2" directive is deprecated, use the "http2" directive instead

Fixes #589 (closed)

roles/archive_web/templates/nginx.d.conf.j2

@@ -16,8 +16,9 @@ server {
 }
 
 server {
-    listen       443 ssl http2;
-    listen       [::]:443 ssl http2;
+    listen       443 ssl;
+    listen       [::]:443 ssl;
+    http2        on;
     server_name  {{ archive_domain }};
 
     access_log   /var/log/nginx/{{ archive_domain }}/access.log reduced;