socketio 第三次握手失败问题

https://segmentfault.com/a/1190000012634779

    location /socket.io {
        proxy_pass http://rqpro_socketio;
        proxy_http_version 1.1;
        proxy_set_header upgrade $http_upgrade;
        proxy_set_header connection $connection_upgrade;
        proxy_set_header x-real-ip $remote_addr;
        proxy_set_header x-forwarded-for $proxy_add_x_forwarded_for;
        proxy_set_header host $http_host;
        proxy_set_header x-nginx-proxy true;
        proxy_set_header Origin "";
        proxy_read_timeout 86400;
    }