Adjust testing password

[Paultagoras]

Summary

Because of changes to default port behavior, the tests broke. Setting a password for the default user resolves this.

Checklist

Delete items not relevant to your PR:

• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG
• For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials