HPCC-9543 Fix crash caused by fix for issue 9467

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #4539 from ghalliday/issue9543

HPCC-9543 Fix crash caused by fix for issue 9467

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>