Modify migration to take existing realm_vhost into account

[pauldekkers]

Migration Version20230316140730 creates realm_vhost which is likely to exist.

It's better to make that conditional, and while doing so include the other tables as well?

[parijke]

I think you fixed this yourself in this commit https://github.com/geteduroam/letswifi-admin/commit/81f5cc6a75a5b160cd4d48e3a63826614b6062c7