Nginx:avoid Nginx:[warn]0.0.0:80上有冲突的服务器名“index”,忽略

server {
   root /var/www/example/build;
   server_name example.com www.example.com
   index index.html index.htm;
   location / {
      try_files $uri $uri/ /index.html;
   }

    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


   listen 80 default_server;
   server_name example.com www.example.com
   index index.html index.htm;
    return 404; # managed by Certbot
}

当我运行以下命令时: sudo nginx -t 用于检查nginx语法。我遇到这个警告:

nginx: [warn] conflicting server name "index" on 0.0.0.0:443, ignored
nginx: [warn] conflicting server name "index.html" on 0.0.0.0:443, ignored
nginx: [warn] conflicting server name "index.htm" on 0.0.0.0:443, ignored
nginx: [warn] conflicting server name "index" on 0.0.0.0:80, ignored
nginx: [warn] conflicting server name "index.html" on 0.0.0.0:80, ignored
nginx: [warn] conflicting server name "index.htm" on 0.0.0.0:80, ignored

我已经测试过了,发现那些警告并不是问题所在。(因为我监听多个文件上的同一端口)。但我不知道我是否删除了其中一个文件中的侦听端口,有什么问题吗?还有没有其他方法可以禁用此警告。