ShardMap Refresh fails in Cluster of one Node (Master + Replica)

[neeraj97]

Currently the ShardMap refresh happens on only master nodes. So in a Redis cluster of One Node (master + replica) after the Master failover to Slave, the client won't be able to recover from the changes.

[neeraj97]

In cloud it is allowed for a Redis Cluster to have only one Node. But in Redis OSS it has to have minimum of 3.