anchor.diff:        ${optionalString cfg.statusPage ''
           server {
             listen 80;
  -          listen [::]:80;
  +          ${optionalString enableIPv6 "listen [::]:80;" }
   
             server_name localhost;
   
  
positive.code:             stub_status on;
              access_log off;
              allow 127.0.0.1;
              allow ::1;
              deny all;
            }
          }
  
negative.code:         ${optionalString vhost.forceSSL ''
            server {
              listen 80 ${optionalString vhost.default "default"};
              ${optionalString enableIPv6
                ''listen [::]:80 ${optionalString vhost.default "default"};''
              }
  
              server_name ${serverName} ${concatStringsSep " " vhost.serverAliases};
              ${acmeLocation}
  