HPCC-12284 Changed REAL index to index range in hashjoin regression test

Signed-off-by: jamienoss <james.noss@lexisnexis.com>
Merge pull request #6452 from jamienoss/issue12284-range-mistake-in-regress-hashjoin.ecl

HPCC-12284 Changed REAL index to index range in hashjoin regression test

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>