This corresponds to NEO/py commit ef5fc508 (Make the number of replicas
modifiable when the cluster is running).

One important change in the protocol is that Client no longer queries
Master for partition table - instead M pushed partTab to C right after
identification (after pushing nodeTab).

See also: https://neo.nexedi.com/P-NEO-Protocol.Specification.2019?portal_skin=CI_slideshow#/9/5