HPCC-12178 Fix format string and add braces to clarify if

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #6417 from ghalliday/issue12178

HPCC-12178 Fix format string and add braces to clarify if

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>