Don't version_check metadata db

Created by: james-monkeyshines

Description

The metadata database is unversioned, and exists apart from the release cycle. So the version check is not required.

Use case

Loading the metadata db in the registry gives warnings about a missing db version.

Benefits

Incorrect warnings are removed.

Possible Drawbacks

None

Testing

No new test, it's a minor change. registry.t passes.