This will add `passthru.schema_version` to be used as default value for
the adguardhome module.
It will also update the `update.sh` to keep the `schema_version` in sync
with the version by inspecting the sourcecode.
This might break existing configs, if they use deprecated values that don't
appear in newer schema_versions and schema_version wasn't set explicitly.
Explicit declarations of schema_version always have higher priority.
This also removes the `host` and `config` settings in favour of using the
appropriate `settings`.
Fixes#173938
Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
