CBQE-927: increase wait warmup timout after upgrade for linux

Change-Id: I9ba42d0878ce2f8a9b8115935b050d533c311256
Reviewed-on: http://review.couchbase.org/25020
Reviewed-by: Andrei Baranouski <andrei.baranouski@gmail.com>
Tested-by: Andrei Baranouski <andrei.baranouski@gmail.com>