Distributed sync non-tx cache.
Situation:

1) A node is joining the cluster, requesting some segment
2) RemoveCommand is sent to backup owner with ignorePreviousValue=true
3) It looks up the entry and finds null
4) State transfer invokes the PutKeyValueCommand and sets the value for removed entry (updateKeys has not the key yet)
5) RemoveCommand adds its key to updateKeys set, but it does not remove the value as it is already null (in its context)

Result: the value is removed on primary but on backup this is still present