cbqe-0: add to n1ql conf let tests

Change-Id: I630bfae138899166fc6349312dc592ebd00b7a37
Reviewed-on: http://review.couchbase.org/43284
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Iryna Mironava <irynamironava@yandex.ru>