Adapting test case for the latest observe changes.

Change-Id: I0dab4692c29411d96ddea5297d8fd2959640626b
Reviewed-on: http://review.couchbase.org/30045
Tested-by: Michael Nitschinger <michael.nitschinger@couchbase.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>