Passenger Vhost server config example have issue with cloning subgroup - Bring it up to date.

Following the Passenger Vhost server block example configuration closely, we have customer having issue cloning from subgroups.

Looking at the repo, it seems like most of them have not been updated since 2015

To Do:

1. Consider if this is the right page for this server block

• The examples for non-bundled web-server link out to a repo

1. Update it to work better with how GitLab work currently

Ticket: https://gitlab.zendesk.com/agent/tickets/301140