HPCC-10164 Don't substitute constants into ATMOST join conditions

This should be improved later (see HPCC-10166), but this fixes the compile
errors.

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #4953 from ghalliday/issue10164

HPCC-10164 Don't substitute constants into ATMOST join conditions

Reviewed-By: Jamie Noss <james.noss@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>