Fixed jpg cache fail to decode panic bug

mod/filesystem/metadata/folder.go

@@ -79,8 +79,10 @@ func generateThumbnailForFolder(cacheFolder string, file string, generateOnly bo
 
 	topImage, err := jpeg.Decode(image3)
 	if err != nil {
-		//Fail to decode the image. Maybe damaged
+		//Fail to decode the image. Try to remove the damaged iamge file
+		image3.Close()
 		os.Remove(contentCache[0])
+		log.Println("Failed to decode cahce image for: " + contentCache[0] + ". Removing thumbnail cache")
 		return "", errors.New("failed to decode: " + err.Error())
 	}
 	defer image3.Close()