HPCC-8586 Remove code that tries to percolate maxlength when projecting

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #4106 from ghalliday/issue8586

HPCC-8586 Remove code that tries to percolate maxlength when projecting

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>