fixup! multi: Support custom size onion packets

Author: gijswijs

error.go

@@ -39,7 +39,7 @@ var (
 
 	// ErrNegativeRoutingInfoSize is returned when a negative routing info
 	// size is specified in the Sphinx configuration.
-	ErrNegativeRoutingInfoSize = errors.New("payload size must be " +
+	ErrNegativeRoutingInfoSize = errors.New("routing info size must be " +
 		"non-negative")
 
 	// ErrNegativePayloadSize is returned when a negative payload size is