Fix EZP-23651 - EZ Si missing /var/[^]+/cache/public

### EZP-23651 - EZ Si missing /var/[^]+/cache/public

This PR addresses the issue https://jira.ez.no/browse/EZP-23651

The virtualhosts example in ezsi extension, https://github.com/ezsystems/ezsi/blob/master/doc/documentation.rst#virtualhost-example, don't mention the RewriteRule ^/var/([^/]+/)?cache/public/.* - [L]