chaindb: better rescan algo.
chaindb: better rescan algo.

decentraland/bronzeage-node,VidaID/bcoin,decentraland/bronzeage-node,decentraland/bronzeage-node,VidaID/bcoin,decentraland/decentraland-node,decentraland/decentraland-node,VidaID/bcoin,decentraland/decentraland-node