Switching language during a level does not affect current objectives and information messages

[AdamPlenty]

1. Start a level with support for multiple languages (original campaign or Deeper Dungeons will do)
2. Save the game
3. Quit the game and switch to another supported language
4. Start the game and load the save

Current objectives and information messages will still be in the original language; only newly triggered ones will be in the new language. If the old language uses a different encoding, the messages will may as gibberish (though that's a separate issue).