remove strange sanity check

importer/normalize.go

@@ -50,7 +50,7 @@ func (job *Job) normalize(loudness interface{}) error {
 		}
 
 		srcStat, err := src.Stat()
-		if err != nil || srcStat.Size() < 0 {
+		if err != nil {
 			done <- err
 			return
 		}