anchor.diff:  server {
  -  listen <%= @listen %>;
  +  listen <%= @listen %> <%= 'ssl' if  @redirect_http_https %>;
     <% if @server_name %>
     server_name <%= @server_name %>;
     <% end %>
  
positive.code: server {
    listen 80;
    server_name <%= @server_name %>;
    rewrite ^(.*) https://$host$1 permanent;
  }
  <% end %>
negative.code:   <% if @client_body_buffer_size %>
    client_body_buffer_size <%= @client_body_buffer_size %>;
    <% end %>
  
    gzip_static on;
  
    <% if @ssl_certificate %>
  