Fix nextcloud X-Frame-Options warning

nextcloud.subdomain.conf.sample

@@ -1,4 +1,4 @@
-## Version 2021/05/18
+## Version 2022/10/28
 # make sure that your dns has a cname set for nextcloud
 # assuming this container is called "swag", edit your nextcloud container's config
 # located at /config/www/nextcloud/config/config.php and add the following lines before the ");":
@@ -31,6 +31,7 @@ server {
         set $upstream_proto https;
         proxy_pass $upstream_proto://$upstream_app:$upstream_port;
 
+        proxy_hide_header X-Frame-Options;
         proxy_max_temp_file_size 2048m;
     }
 }