Fix documentation for connecting to multiple devservice databases

[albers]

I had some difficulties connecting to the devservices databases of a service with multiple datasources because the documentation in the Dev Services for Databases guide is wrong.

How to verify

Inspect the devservice database containers of a multi-datasource application with docker inspect.

Here are the env vars of the postgres container for the named datasource "db1":

$ docker container inspect unruffled_franklin --format '{{json .Config.Env}}' | jq -r '.[]' | grep POSTGRES
POSTGRES_USER=quarkus
POSTGRES_PASSWORD=quarkus
POSTGRES_DB=db1

For reference, these are the corresponding env vars from a devservices container for the default database in a single-datasource setup:

$ docker container inspect clever_murdock --format '{{json .Config.Env}}' | jq -r '.[]' | grep POSTGRES
POSTGRES_USER=quarkus
POSTGRES_PASSWORD=quarkus
POSTGRES_DB=quarkus

This PR fixes the issue.

[github-actions]

🙈 The PR is closed and the preview is expired.

[quarkus-bot]

Status for workflow Quarkus Documentation CI

This is the status report for running Quarkus Documentation CI on commit 6a63d8b.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

[gsmet]

Ah, right, good catch!