HPCC-11090 Fix build break when unit testing enabled

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #5589 from ghalliday/issue11090

HPCC-11090 Fix build break when unit testing enabled

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>