There are two simple ways to fix this:
1) if you don't care about the data stored in PostgreSQL, completely remove the image: `docker rm <image-name>` (alternatively, drop all the tables) -- the goal is to start from a completely clean slate
2) if you want to keep any data currently in the database, add this environment variable to the Trellis service:
QUARKUS_FLYWAY_BASELINE_ON_MIGRATE = "true"
The issue has to do with the fact that the dropwizard-based Trellis image (trellisldp/trellis) uses Liquibase to manage database schema migrations while the Quarkus-based image (trellisldp/trellis-postgresql) uses Flyway. The data schemas themselves are identical, but Flyway complains if you start using it with a database that has existing tables. The environment variable only needs to be used once; then you can remove it from the docker compose configuration.
Hope that helps,