`bot.DeleteWebhook()` method is not working in v1.17.0

[Interstellar750]

My bot had been using Webhook mode, but due to the Cloudflare network outage today, I thought I could switch to long polling mode to proactively get updates.

But after calling the bot.DeleteWebhook() method, it output some errors:

{
  "level": "error", "time": "2025-11-18T20:51:42+08:00",
  "error": "error decode response body for method deleteWebhook, , unexpected end of JSON input",
  "message": "Failed to delete Webhook URL"
}

I tried using the bot.WithDebug() option to see some details, but it just output a single line of log data:

2025/11/18 20:48:09 [TGBOT] [DEBUG] request url: https://api.telegram.org/bot***/deleteWebhook, payload: {}

I remember it working before, so I tried rolling back to version v1.16.0, and it worked fine.

Is the problem caused by the change in #205?

[stalkerxxl]

I confirm there is such a problem

[qwerty22121998]

Confirm this is a bug, can workaround by passing nil to param