server-configs-nginx/sites-available/ssl.no-default

# Drop requests for unknown hosts
#
# If no default server is defined, nginx will use the first found server.
# To prevent host header attacks, or other potential problems when an unknown 
# servername is used in a request, it's recommended to drop the request 
# returning 444 "no response".

server {
  listen 443 ssl default_server;
  include h5bp/directive-only/ssl.conf
  return 444;
}