v4.0.4

## v4.0.4 (Jul 1, 2022)
- Changed `GroupChannel.createScheduledUserMessage()` and `GroupChannel.createScheduledFileMessage()` to return a `MessageRequestHandler` instance.
- An optional property `scheduledMessageParams` has been added to `ScheduledInfo`.
- Fixed a bug where `succeededMessage.replyToChannel` is false when a message is sent with `messageParams.isReplyToChannel` set to true.
- Improved stability.