CBQE-2497: update n1ql index tests

Change-Id: I4a9903d69dd2db7fa90204566d4dfca4fff5716a
Reviewed-on: http://review.couchbase.org/44655
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>