fix(bot): make proxy/log blacklists work properly with threads

Handling of both blacklists was inconsistent when dealing with threads:
- proxy blacklist of root channel blacklists all threads
- log blacklist of root channel _did not apply_ to threads
- couldn't proxy blacklist threads while leaving root channel proxyable

This change fixes the inconsistencies:
- proxy _and_ log blacklist of root channel affects all threads
- now able to individually proxy/log blacklist threads, with root
  channel unaffected

PluralKit.Bot/Handlers/MessageCreated.cs

@@ -159,7 +159,7 @@ public class MessageCreated: IEventHandler<MessageCreateEvent>
         // Get message context from DB (tracking w/ metrics)
         MessageContext ctx;
         using (_metrics.Measure.Timer.Time(BotMetrics.MessageContextQueryTime))
-            ctx = await _repo.GetMessageContext(evt.Author.Id, evt.GuildId ?? default, rootChannel);
+            ctx = await _repo.GetMessageContext(evt.Author.Id, evt.GuildId ?? default, rootChannel, channel.Id != rootChannel ? channel.Id : default);
 
         try
         {