config: chatrooms no logging by default

[slook]

The "rooms" setting is sufficient for remembering to log particular chat rooms if desired, otherwise superfluous plain text data (containing massive amounts of spam) is written to disk, perhaps without user knowledge.

• Changed: config.defaults["logging"]["chatrooms"] = False

See discussion #2519 wherein @j-minster raises valid concerns about the nature of plain text data generated by other users who tend to aggressively exercise their right to freedom of speech in the default room, that is persistently written onto local disk by the application.

[mathiascode]

Seeing how the room has changed in the past few years, and the increasing number of new users, I'd be in favor of simply removing the nicotine room from the list of auto-joined rooms. I don't think most people care about the room or even notice that they've joined it, and it's still at the top of the list for anyone who wants to join it.

Some concerns I have:

• Server traffic related to joining, leaving, as well as status/stat updates
• Increasing amount of spam and garbage in the room
• Large list of users for spambots to target

Removing the room from auto-joins would only affect new installations. We don't want to force such a change on existing configs.