CBLT-329:  change target to match build tools 19.1.0

Change-Id: I01f6b73716f3c3ce9841d2ead94ab686e3c4dff5
Reviewed-on: http://review.couchbase.org/40503
Reviewed-by: Philip Labee <philip@couchbase.com>
Tested-by: Philip Labee <philip@couchbase.com>