CBQE-0: minor fix in membase_upgrade_win, increase timeout for 1.8.0 upgrade

Change-Id: I5b9d35941130ba1dd56158685ff9d851ce31c2f1
Reviewed-on: http://review.couchbase.org/27019
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>