Wait for replication_active_vbreps/xdc_ops to >= 0

- pauseResumeXDCR

Change-Id: If8166ef89b8d0bbad77a411270a6e866afbccf18
Reviewed-on: http://review.couchbase.org/38214
Reviewed-by: Aruna Piravi <aruna@couchbase.com>
Tested-by: Aruna Piravi <aruna@couchbase.com>