website/docs: Upgrade nginx reverse porxy config (#8947)

Update reverse-proxy.md

Signed-off-by: Vince <wlmqpsc@gmail.com>

website/docs/installation/reverse-proxy.md

@@ -56,7 +56,7 @@ server {
         proxy_http_version 1.1;
         proxy_set_header X-Forwarded-Proto $scheme;
         proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
-        proxy_set_header Host $host;
+        proxy_set_header Host $http_host;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection $connection_upgrade_keepalive;
     }