Resolve deprecations for the `RabbitListenerErrorHandler`

[artembilan]

Now its definition supposed to be like:

		@Bean
		public RabbitListenerErrorHandler rleh() {
			return (amqpMessage, channel, message, exception) -> null;
		}

and AmqpHeaders.CHANNEL header is not needed in the Message<?> any more.

[artembilan]

Related to #2652