cql2pgjson tries to use Postgres 5433 5432 ports by default

It's quite weird. cql2pgjson's DatabaseTestBase.java has logic where it uses Postgres on 5432 5433 when we have embedded testing (whether containers or not).

Suggestion.. and in sync with rest of RMB.. Use tester by default.
If DB_HOST is defined - use other DB_-settings in that test and FAIL if that does not work.
(never switch to Postgres tester if DB_HOST defijned).

This allows somebody to test against a local postgres if so desired, but have deterministic and faster processing (no need check for Postgres on 5433, 5432)..