HPCC-11992 Regression Test Engine crashed in Overnight Build

Implement fix.

Signed-off-by: Attila Vamos <attila.vamos@gmail.com>
Merge pull request #6288 from AttilaVamos/HPCC-11992-fix

HPCC-11992 Regression Test Engine crashed in Overnight Build

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>