Add error message for when service isn't authorized by cftools app

[schana]

Currently the bot fails silently

2020-10-14 10:22:54,224 ERROR carim_discord_bot.managed_service - something crashed OmegaService
Traceback (most recent call last):
  File "C:\Users\Nathaniel\Documents\carim-discord-bot\src\carim_discord_bot\managed_service.py", line 68, in _message_processor
    await self._handle_message(message)
  File "C:\Users\Nathaniel\Documents\carim-discord-bot\src\carim_discord_bot\managed_service.py", line 77, in _handle_message
    await self.handle_message(message)
  File "C:\Users\Nathaniel\Documents\carim-discord-bot\src\carim_discord_bot\cftools\omega_service.py", line 94, in handle_message
    result = await self.query_leaderboard(message.server_name, message.stat)
  File "C:\Users\Nathaniel\Documents\carim-discord-bot\src\carim_discord_bot\cftools\omega_service.py", line 177, in query_leaderboard
    service_token = self.get_service_token(server_name)
  File "C:\Users\Nathaniel\Documents\carim-discord-bot\src\carim_discord_bot\cftools\omega_service.py", line 152, in get_service_token
    return self.service_tokens[config.get_server(server_name).cftools_service_id]
KeyError: None