message: check lock.i against null specifically
diff: @@ -157,7 +157,7 @@ export class DiscordBot {
  public unlockChannel(channel: Discord.Channel) {
  const lock = this.channelLocks[channel.id];
  - if (lock && lock.i) {
  + if (lock && lock.i !== null) {
  clearTimeout(lock.i);
  }
  delete this.channelLocks[channel.id];
  