传入的主机头加倍

我在带有 Gunicorn 和 Django 的 Ubuntu 18.04 服务器上使用 Nginx 网络服务器。我的服务器当前已关闭，因为传入的主机标头总是重复的。

当我向服务器发出请求时，我收到 Django 的错误提示

Invalid HTTP_HOST header: 'dt-testing.com,dt-testing.com'. The domain name provided is not valid according to RFC 1034/1035.

我无法弄清楚传入标头在哪里被加倍。我已经尽我所能梳理了我的 nginx.conf 和 sites-available 文件，但根本找不到任何可疑的东西。

站点可用文件：

#server { # redirection logic
#        listen 80; # port to listen on
#        #return 301 https://$host$request_uri*;
#        return 301 https://$host$request_uri; # could this be causing the doubling of the URL?
#}

server {
#    listen 443 ssl; # listen for HTTPS
    listen 80; # listen for HTTPS
    server_name dt-testing.com www.dt-testing.com; # server name to use

    location = /favicon.ico { access_log off; log_not_found off; } # site icon to use
    location /static/ { # location of static files
        root /websites/DT/DiamondTutoring/;
    }

    location / { # error is here?
        proxy_pass http://unix:/websites/DT/run/gunicorn.sock; # connector to gunicorn
        proxy_set_header Host $host;
        include proxy_params;
        #error_page 405 =200 $uri;
    }

#    ssl_certificate /etc/letsencrypt/live/dt-testing.com/fullchain.pem; # managed by Certbot
#    ssl_certificate_key /etc/letsencrypt/live/dt-testing.com/privkey.pem; # managed by Certbot


    rewrite_log on;
    error_log /var/log/nginx/error_log;

}

nginx.conf 文件

user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;

events {
    worker_connections 768;
    # multi_accept on;
}



http {

    ##
    # Basic Settings
    ##
    sendfile on;
    tcp_nopush on;
    tcp_nodelay on;
    keepalive_timeout 65;
    types_hash_max_size 2048;
    # server_tokens off;

    # server_names_hash_bucket_size 64;
    # server_name_in_redirect off;

    include /etc/nginx/mime.types;
    default_type application/octet-stream;

    ##
    # SSL Settings
    ##

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
    ssl_prefer_server_ciphers on;

    ##
    # Logging Settings
    ##

    access_log /var/log/nginx/access.log;
    error_log /var/log/nginx/error.log;

    ##
    # Gzip Settings
    ##

    gzip on;

    # gzip_vary on;
    # gzip_proxied any;
    # gzip_comp_level 6;
    # gzip_buffers 16 8k;
    # gzip_http_version 1.1;
    # gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    ##
    # Virtual Host Configs
    ##

    #include /etc/nginx/conf.d/*.conf;
    include /etc/nginx/sites-enabled/*;
}


#mail {
#   # See sample authentication script at:
#   # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
# 
#   # auth_http localhost/auth.php;
#   # pop3_capabilities "TOP" "USER";
#   # imap_capabilities "IMAP4rev1" "UIDPLUS";
# 
#   server {
#       listen     localhost:110;
#       protocol   pop3;
#       proxy      on;
#   }
# 
#   server {
#       listen     localhost:143;
#       protocol   imap;
#       proxy      on;
#   }
#}

有什么我想念的吗？我无法弄清楚标头在哪里会被复制并连接在一起。