如何在不提供nginx中的ssl证书的情况下设置https上游？

Question

我想将进入端口80上运行的服务器的所有请求重定向到运行端口443的上游。

我正在尝试使用以下配置。但它不起作用

worker_processes  1;
events {
    worker_connections  1024;
}
http {
    include       mime.types;
    keepalive_timeout  65;
    client_max_body_size 500M;
    #timeouts
    proxy_connect_timeout       600;
    proxy_send_timeout          600;
    proxy_read_timeout          1m;
    send_timeout                600;
    upstream backend {
      server developers.facebook.com:443;
      keepalive 64;
    }
    #
    # The default server
    #
    server {
      listen   80;
      server_name  http_server;
      error_log  /var/log/nginx/error.log debug;
      location /products {
            rewrite ^/products/(.*) /$1/$2 break;
            proxy_pass https://backend;
            proxy_redirect off;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Proto $scheme;
            proxy_set_header   Host   $http_host;
            proxy_set_header   X-NginX-Proxy true;
            real_ip_header     X-Forwarded-For;
            real_ip_recursive  on;
            #proxy_set_header   Connection "";
            #proxy_http_version 1.1;
            proxy_ssl_protocols           TLSv1 TLSv1.1 TLSv1.2;
            proxy_ssl_ciphers             HIGH:!aNULL:!MD5;
            proxy_ssl_verify        on;
            proxy_ssl_verify_depth  2;
            proxy_ssl_session_reuse on;
          }
        # redirect not found pages to the static page /404.html
        error_page  404  /404.html;
        location = /404.html {
            root   /usr/share/nginx/html;
        }
        # redirect server error pages to the static page /50x.html
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   /usr/share/nginx/html;
        }
    }
}

我尝试使用sudo nginx -t -c /etc/nginx/nginx.conf验证nginx配置时出现以下错误，

nginx: [emerg] unknown directive "proxy_ssl_verify" in /etc/nginx/nginx.conf:44
nginx: configuration file /etc/nginx/nginx.conf test failed

我是否需要提供证书才能访问developers.facebook.com:443？

我正在使用nginx version: nginx/1.6.2

有人可以帮我这个吗？