don't crash if no thumbnail provided. lol

+ neat --verbose message if a thumbnail *is* provided

main.go

@@ -208,12 +208,15 @@ func main() {
 	var thumbnail *yt.ThumbnailMetadata
 	thumbnailPath, thumbnailSizeBytes, err := scanner.ScanThumbnail(directory)
 	if err != nil {
+		if !os.IsNotExist(err) {
 			log.Fatalf("Failed to fetch thumbnail: %v", err)
+		}
 	} else {
 		thumbnail = &yt.ThumbnailMetadata{
 			Filepath: thumbnailPath,
 			SizeBytes: thumbnailSizeBytes,
 		}
+		log.Printf("Thumbnail detected. This will be applied after VOD upload.")
 	}
 
 	// build video template for upload