Add an apparently important setting for websocket connections.

host.tpl

@@ -14,6 +14,7 @@ server {
 
   location / {
     proxy_pass http://localhost:{{.InternalPort}}/;
+    proxy_http_version 1.1;
     proxy_set_header Upgrade $http_upgrade;
     proxy_set_header Connection upgrade;
     proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;