Fix nginx adding trailing slash before request params

See https://superuser.com/questions/1766950/how-to-remove-trailing-slash-before-url-parameters-in-nginx

and

https://nginx.org/en/docs/http/ngx_http_core_module.html#location

frontend/nginx.conf

@@ -8,7 +8,7 @@ server {
   server_name _;
   root /app/build/client;
 
-  location / {
+  location ~ .*$ {
     try_files $uri $uri/ @sveltekit;
   }