I have found this working configuration:
location /http-bind {
proxy_pass http://sapbot.mo.sap.corp:5280/http-bind;
proxy_set_header Host $host;
proxy_buffering off;
tcp_nodelay on;
}
location / {
proxy_pass http://localhost:8000;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_redirect http://$server_name http://$server_name:8000;
}