Panic on bot.Stop() v4.0.0-beta.4

[ofstudio]

panic: close of closed channel
goroutine 44 [running]:
gopkg.in/telebot%2ev4.(*Webhook).waitForStop(...)
	gopkg.in/telebot.v4@v4.0.0-beta.4/webhook.go:161
gopkg.in/telebot%2ev4.(*Webhook).Poll.func1(0xc000450a10)
	gopkg.in/telebot.v4@v4.0.0-beta.4/webhook.go:148 +0x2f
created by gopkg.in/telebot%2ev4.(*Webhook).Poll in goroutine 40
	gopkg.in/telebot.v4@v4.0.0-beta.4/webhook.go:147 +0x18a

the code

go bot.Start() // 1. Start the bot
<-ctx.Done()   // 2. Wait for context cancel on SIGING or SIGTERM
bot.Stop()     // 3. Stop the bot
// ^^^^ Panic goes here!