example.com перенаправил вас слишком много раз. ERR_TOO_MANY_REDIRECTS

Question

Я пытался защитить Nginx с помощью Let's Encrypt в Ubuntu 16.04.

файл example.conf до получения SSL-сертификата

server {
    server_name example.com www.example.com ;
    # Tell Nginx and Passenger where your app's 'public' directory is
    root /var/www/backup/mycode/public;
    # Turn on Passenger
    passenger_enabled on;
    rails_env development;
    passenger_ruby /usr/local/rvm/gems/ruby-2.5.6/wrappers/ruby;

}

http://example.com/ это работает нормально.

Я пытаюсь получить сертификат SSL по

sudo certbot --nginx -d example.com -d www.example.com

результат был

Your existing certificate has been successfully renewed, and the new certificate
has been installed.

The new certificate covers the following domains: https://example.com and
https://www.example.com

файл example.conf после получения сертификата SSL

server {
    server_name example.com www.example.com ;
    # Tell Nginx and Passenger where your app's 'public' directory is
    root /var/www/backup/example.com/public;
    # Turn on Passenger
    passenger_enabled on;
    rails_env development;
    passenger_ruby /usr/local/rvm/gems/ruby-2.5.6/wrappers/ruby;




    listen 443 ssl; # managed by Certbot
    ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
    include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

}
server {
    if ($host = www.example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    if ($host = example.com) {
        return 301 https://$host$request_uri;
    } # managed by Certbot


    server_name example.com www.example.com ;
    listen 80;
    return 404; # managed by Certbot

}

http://example.com/ перенаправляет на https://example.com/ слишком много раз

example.com redirected you too many times.
ERR_TOO_MANY_REDIRECTS

1. Почему он перенаправляет слишком много раз?

2. для чего предназначен второй блок сервера?

   server {
   if ($host = www.example.com) {
       return 301 https://$host$request_uri;
   } # managed by Certbot
   
   
   if ($host = example.com) {
       return 301 https://$host$request_uri;
   } # managed by Certbot
   
   
   server_name example.com www.example.com ;
   listen 80;
   return 404; # managed by Certbot
   
    }
   

3. Как сделать все перенаправления на https://www.example.com/?