revid-cli: initialising config.Output slice when no outputs are defined so that a default output can still be set

cmd/revid-cli/main.go

@@ -184,6 +184,10 @@ func handleFlags() revid.Config {
 		log.Log(logger.Error, pkg+"bad input codec argument")
 	}
 
+	if len(outputs) == 0 {
+		cfg.Outputs = make([]uint8, 1)
+	}
+
 	for _, o := range outputs {
 		switch o {
 		case "File":