CBQE-0: decrease items in xdcrview tests

Change-Id: I6f5c34d438167784f4295fa9179f3e4e979e1f3f
Reviewed-on: http://review.couchbase.org/44103
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Ketaki Gangal <ketakigangal@gmail.com>