Make CoordinatorStreamSystemConsumer skip error messages

Not sure if it's a good idea. Looking for some feedbacks.

There are two reasons in my mind:

1. when users accidentally publish error-messages to the coordinatorStreamConsumer, there is no easy way to remove that messages, this breaks the whole system because we wont be able to run the bootstrap() successfully.

2. if the coordinator messages are not serialized correctly, this breaks the bootstrap() as well.