location  / {         proxy_redirect off;         proxy_set_header Host $host;         proxy_set_header X-Real-IP $remote_addr;         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;                   client_max_body_size 50m;         client_body_buffer_size 256k;         proxy_http_version 1.1;         proxy_pass http://1.2.3.4:8080;        }