fixed forward prefix

examples/nginx_subpath/nginx.conf

@@ -50,7 +50,7 @@ http {
             proxy_pass_header  Authorization;
 
             proxy_pass http://app:8080/$1?$args;
-            proxy_set_header X-Forwarded-Prefix /nicegui/$1/;
+            proxy_set_header X-Forwarded-Prefix /nicegui/;
         }
     }
 }