CBQE-0: Fix xdcr.biXDCR.load_with_async_ops_and_joint_sets tests

Change-Id: I40de2d4c07c5599681e5ea37cf1049f65198734b
Reviewed-on: http://review.couchbase.org/40266
Reviewed-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>
Tested-by: Sangharsh Agarwal <sangharsh.agarwal@globallogic.com>