eth: don't print db upgrade warning on db init

eth/backend.go

@@ -165,7 +165,9 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 		if bcVersion != nil && *bcVersion > core.BlockChainVersion {
 			return nil, fmt.Errorf("database version is v%d, Geth %s only supports v%d", *bcVersion, params.VersionWithMeta, core.BlockChainVersion)
 		} else if bcVersion == nil || *bcVersion < core.BlockChainVersion {
-			log.Warn("Upgrade blockchain database version", "from", dbVer, "to", core.BlockChainVersion)
+			if bcVersion != nil { // only print warning on upgrade, not on init
+				log.Warn("Upgrade blockchain database version", "from", dbVer, "to", core.BlockChainVersion)
+			}
 			rawdb.WriteDatabaseVersion(chainDb, core.BlockChainVersion)
 		}
 	}