Fix nodelist initialization accumulator
Fix nodelist initialization accumulator

The tree fold returned a malformed accumulator in the case of deleted
nodes or design documents in the nodes database.  This would crash mem3
immediately and prevent the node from starting up.

BugzID: 12576

fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb,fkaempfer/couchdb