JSCBC-1092: Fix queries to default to adhoc rather than prepared.
JSCBC-1092: Fix queries to default to adhoc rather than prepared.

Motivation
----------
The 3.x SDK and SDK design guidelines describe that queries should
be adhoc by default, and should only prepare queries when explicitly
requested.

Changes
-------
Changed the adhoc value calculation to default appropriately.

Change-Id: I189c967039c824224a5b3036bef0f77a2e642a13
Reviewed-on: https://review.couchbase.org/c/couchnode/+/178493
Reviewed-by: Charles Dixon <e13bf4498b4994e133fd3586350658dc4a59329a@gmail.com>
Tested-by: Brett Lawson <c8c4369773d7d7226e031f0c4af62e3f38a08510@gmail.com>

couchbase/couchnode,couchbase/couchnode,couchbase/couchnode,couchbase/couchnode