make a note about restricting channel creation to registered users

lib/hk-util.js

@@ -701,6 +701,7 @@ const handleGetHistory = function (Env, Server, seq, userId, parsed) {
             }
 
             if (msgCount === 0 && !metadata_cache[channelName] && Server.channelContainsUser(channelName, userId)) {
+                // TODO this might be a good place to reject channel creation by anonymous users
                 handleFirstMessage(Env, channelName, metadata);
                 Server.send(userId, [0, HISTORY_KEEPER_ID, 'MSG', userId, JSON.stringify(metadata)]);
             }