HPCC-10038 failIfNoSourceFile parameter missing in DFUPlus help text.

Add missing help text.

Signed-off-by: Attila.Vamos <attila.vamos@gmail.com>
Merge pull request #4829 from AttilaVamos/HPCC-10038-fix

HPCC-10038 failIfNoSourceFile parameter missing in DFUPlus help text.

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>