retry method
Starts a finished or failed task over from byte zero.
Implementation
Future<void> retry(String id) async {
final UDownloadTask? task = this.task(id);
if (task == null || task.isActive) return;
await _deletePart(task);
task
..segments.clear()
..received = 0
..total = -1
..error = null
..mirrorIndex = 0
..status = UDownloadStatus.queued;
_changed(task);
_pump();
}