CBQE-2498: n1ql index tests update

Change-Id: Iaef81dc435d2a65f046ecd063c93db2d64a35667
Reviewed-on: http://review.couchbase.org/44659
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>
Tested-by: Iryna Mironava <irynamironava@yandex.ru>