Simple Passcode login form is shown even when Simple Passcode is turned off

[ispyropoulos]

I just encountered this serious bug on my iOS client and I basically locked myself out.

Steps to reproduce:

1. Settings > Privacy & security > Passcode & Touch ID
2. Turn on passcode
3. Input a 4 digit passcode, twice
4. Switch on Touch ID (otherwise you won’t be able to login at all)
5. Turn off Simple Passcode option
6. Enter a complex passcode, twice

Now, if you lock your chats or time out period expires you will be presented with the 4 digit input form (or the Touch ID input)! You are now locked out of managing your passcode forever...

iOS 12.1.2
Telegram 5.1.1