Plesk 11.x / Linux :: Error When Changing Nginx Configuration

I have following problem when I try to cange the configuration file for Nginx in Plesk.

Details:

- Using Wordpress
- vServer
- PHP is handled through Nginx
- Memcached is enabled

To use the caching plugin "Cachify" in combination with memcached, the nginx configuration file must be edited. Following config should be used:

Code:

## GZIP
gzip_static on;
## CHARSET
charset utf-8;
## INDEX LOCATION
location / {
error_page 405 = @nocache;

[Code] ....

When I try to save the new config, following error appears:

Invalid nginx configuration: nginx: [emerg] duplicate location "/" in /var/www/vhosts/systemmydomain/conf/vhost_nginx.conf:8 nginx: configuration file /etc/nginx/nginx.conf test failed

How can I use the necessary configuration? I used google before, but some people said, that the server templated needs to be edited?