connstr: use Py3's print

Change-Id: I350f8d46f954a9be2c40e9a5b96bdad29964d611
Reviewed-on: http://review.couchbase.org/42294
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
Reviewed-by: Volker Mische <volker.mische@gmail.com>