Vhost config does not inherit defaults from the main configuration

Description of problem:

In ocserv, options (with scope vhost) set in the main configuration are not automatically inherited by named vhosts when those vhosts do not specify the option. Each vhost is treated as a standalone configuration.

This differs from Apache's and Nginx behavior and can be confusing and unexpected.

Expected behavior: A named vhost that does not specify an option should fall back to the value set in the main configuration.