[BUG] Constantly fail to upload file

[SinoAHpx]

怎么复现？

bot.MessageReceived
    .OfType<GroupMessageReceiver>()
    .Subscribe(async r =>
{
    if (r.MessageChain.GetPlainMessage() == "/send")
    {
        var localPath = @"C:\Users\ahpx\Desktop\RandomChoiceGenerator.exe";
        var file = await FileManager.UploadFileAsync(r.GroupId, localPath);
        await r.SendMessageAsync($"The file has been uploaded. \r\n{file.ToJsonString()}");
    }
});

• mirai-api-http 2.5.0
• mirai & mirai-console 2.11.0-M1
• mcl 1.2.2

Existing issue: https://github.com/project-mirai/mirai-api-http/issues/553