webserver: Enable HTTP/2

webserver/templates/sites/hostnamerewrite.conf

 server {
     listen 80;
-    listen 443 ssl;
+    listen 443 ssl http2;
     server_name {{server.forward_hostnames.hostnames|default(server.forward_hostnames)|join(" ")}};
     error_log /var/log/nginx/rewrite-error-{{server.forward_hostnames.hostnames|default(server.forward_hostnames)|first}}.log;
     {% if server.buffer_access_log|default(webserver_buffer_access_log|default(False)) %}

webserver/templates/sites/iprewrite.conf

 server {
     listen 80 {{ 'reuseport' if webserver_enable_reuseport and not webserver_enable_acme_default else '' }};
-    listen 443 ssl {{ 'reuseport' if webserver_enable_reuseport else '' }};
+    listen 443 ssl http2 {{ 'reuseport' if webserver_enable_reuseport else '' }};
     server_name {{ansible_all_ipv4_addresses|join(" ")}};
     error_log /var/log/nginx/rewrite-error-{{ansible_all_ipv4_addresses|first}}.log;
     {% if server.buffer_access_log|default(webserver_buffer_access_log|default(False)) %}

webserver/templates/sites/tlsproxy.conf

 server {
-    listen {% if server.no_ssl is undefined or not server.no_ssl %}443 ssl{% else %}80{% endif %};
+    listen {% if server.no_ssl is undefined or not server.no_ssl %}443 ssl http2{% else %}80{% endif %};
     server_name {{server.server_names|default([server.server_name])|join(" ")}};
     error_log /var/log/nginx/proxy-error-{{server.server_names|default([server.server_name])|first}}.log;
     {% if server.buffer_access_log|default(webserver_buffer_access_log|default(False)) %}