[V3 General] urban command throws an error if the message is deleted before menu timeout

[MeatyChunks]

Command bugs

Command name

urban

What cog is this command from?

general

What were you expecting to happen?

The bot should silently pass over the error I think.

What actually happened?

The bot finds the dictionary result, if the reply is deleted, an error is thrown when the menu timer expires after 30 seconds.

How can we reproduce this issue?

!urban test
!cleanup self 2
wait the 30 seconds and an error is seen in chat with the following traceback:

ERROR events on_command_error 208: Exception in command 'urban'
Traceback (most recent call last):
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\site-packages\redbot\core\utils\menus.py", line 85, in menu
    timeout=timeout,
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\asyncio\tasks.py", line 362, in wait_for
    raise futures.TimeoutError()
concurrent.futures._base.TimeoutError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\site-packages\discord\ext\commands\core.py", line 61, in wrapped
    ret = await coro(*args, **kwargs)
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\site-packages\redbot\cogs\general\general.py", line 301, in urban
    timeout=30,
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\site-packages\redbot\core\utils\menus.py", line 89, in menu
    await message.clear_reactions()
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\site-packages\discord\message.py", line 748, in clear_reactions
    await self._state.http.clear_reactions(self.id, self.channel.id)
  File "c:\users\Ferret\appdata\local\programs\python\python36\lib\site-packages\discord\http.py", line 211, in request
    raise NotFound(r, data)
discord.errors.NotFound: NOT FOUND (status code: 404): Unknown Message

[Tobotimus]

Resolved by #2344.