datahub 505 HTTP Version Not Supported

I have started datahub with steps from https://datahubproject.io/docs/quickstart

and then add nginx with conf

upstream datahub-front {
    server localhost:9002;
}

server {
    server_name  datahub.myhost.com;

    location / {
        proxy_pass http://datahub-front;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_redirect off;
    }

    listen 80; 
}

all works fine at http://datahub.myhost.com:9002

but at http://datahub.myhost.com

i got

Request URL: https://datahub.myhost.com/
Request Method: GET
Status Code: 505 HTTP Version Not Supported

I thing some cfg set up in nginx can fix the problem. pls help

Here is the config I use for a specific location which targets a specific port on my public server :

location /somelocation/ {
      proxy_pass http://localhost:8080/;
      proxy_http_version 1.1;
      proxy_set_header Upgrade $http_upgrade;
      proxy_set_header Connection 'upgrade';
      proxy_set_header Host $host;
      proxy_cache_bypass $http_upgrade;
  }

In your case, I think that the proxy_path must indicate the real port (9002 in your case), but the $http_upgrade sounds fine for a 505 error too ;)