Merge pull request #2068 from CortexFoundation/dev

cmd/devp2p: fix log output

cmd/devp2p/rlpxcmd.go

@@ -81,7 +81,7 @@ func rlpxPing(ctx *cli.Context) error {
 		}
 		return fmt.Errorf("received disconnect message: %v", msg[0])
 	default:
-		return fmt.Errorf("invalid message code %d, expected handshake (code zero)", code)
+		return fmt.Errorf("invalid message code %d, expected handshake (code zero) or disconnect (code one)", code)
 	}
 	return nil
 }