migration: Do not crash if database is ahead a version

Created by: efritz

Noticed a behavior change. Not sure if we upgraded golang-migrate, but we weren't catching this wrapped error condition.

Currently if you set your db version ahead (or go back to main from a feature branch with a migration) you cannot start you stack. This also means that while this behavior was in effect, customers will not be able to downgrade without first reverting the schema.

This PR ensures that having a higher schema version is a non-fatal condition in frontend startup.