Upgrade nginx proxy http version (kubeflow#597)

Signed-off-by: Griffin-Sullivan <[email protected]>

clients/ui/frontend/nginx.conf

@@ -16,6 +16,7 @@ server {
             proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
             proxy_set_header X-Forwarded-Proto $scheme;
             proxy_pass ${API_URL};
+            proxy_http_version 1.1;
          }
     }