nginx 報錯 The plain HTTP request was sent to HTTPS port

https://hostname:4441

nginx監聽4441端口使用https協議，瀏覽器輸入http://hostname:4441報錯

The plain HTTP request was sent to HTTPS port

原因是如果用戶在使用 http 訪問時，就會報497錯誤，

用error_page 處理一下即可：

server {
    listen       4441 ssl;
    ...
    ...
    error_page  497 https://$host:4441;
}