anchor.diff:          ${optionalString vhost.forceSSL ''
             server {
               listen 80 ${optionalString vhost.default "default"};
  -            listen [::]:80 ${optionalString vhost.default "default"};
  +            ${optionalString enableIPv6
  +              ''listen [::]:80 ${optionalString vhost.default "default"};''
  +            }
   
               server_name ${serverName} ${concatStringsSep " " vhost.serverAliases};
               ${acmeLocation}
  
positive.code:       ${optionalString cfg.statusPage ''
          server {
            listen 80;
            listen [::]:80;
  
            server_name localhost;
  
  
negative.code: 
          server {
            listen ${listenString};
            ${optionalString enableIPv6 "listen [::]:${listenString};"}
  
            server_name ${serverName} ${concatStringsSep " " vhost.serverAliases};
            ${acmeLocation}
  