Nginx Remove WWW And Respond To Both

According to https://www.nginx.com/resources/wiki/start/topics/tutorials/config_pitfalls/#server-name-if, you should use:

server {
  server_name www.example.com;
  return 301 $scheme://example.com$request_uri;
}
server {
  server_name example.com;
  # [...]
}