CBQE-0: changes to catch issue with upgr custom data path

Change-Id: Ia3147c8aae3e27162998793dcdb5417a078b1e6b
Reviewed-on: http://review.couchbase.org/26930
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>