HPCC-9535 Rationalize Roxie topology info

Fix regression in previous commit

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #4552 from richardkchapman/roxie-topology-regression

HPCC-9535 Rationalize Roxie topology info

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>