message: Apply defaults to config if a value doesn't exist.
diff: @@ -45,6 +45,7 @@ function run (port: number, config: DiscordBridgeConfig) {
  if (registration === null) {
  throw new Error("Failed to parse registration file");
  }
  + config = Object.assign({}, new DiscordBridgeConfig(), config);
  const botUserId = "@" + registration.sender_localpart + ":" + config.bridge.domain;
  const clientFactory = new ClientFactory({
  appServiceUserId: botUserId,
  