CBQE-0 remove -rel in build number in url

Change-Id: I141768a8836e210fdaf3aa1ea414a9a78fa2081d
Reviewed-on: http://review.couchbase.org/44557
Reviewed-by: Thuan Nguyen <soccon@gmail.com>
Tested-by: Thuan Nguyen <soccon@gmail.com>