updateRepoSize is only called on the UUID of a repository, not any
cluster it might be a node of. But overLocationLogs and overLocationLogsJournal
were inclusing cluster UUIDs. So it was inconsistent.
Currently I don't see any reason to calculate RepoSize for a cluster.
It's not even clear what it should mean, the total size of all nodes, or
the amount of information stored in the cluster in total?