[ticket/11575] Correct test_cross_join() to test_order_lower().

This test does not do any cross joining, it only tests ORDER BY LOWER(...).

PHPBB3-11575
Merge remote-tracking branch 'bantu/ticket/11575' into develop-olympus

* bantu/ticket/11575:
  [ticket/11575] Correct test_cross_join() to test_order_lower().