INT-3404: Get rid of `MProducer` from `AIFileSMS`

JIRA: https://jira.spring.io/browse/INT-3404

Before `AbstractInboundFileSynchronizingMessageSource` implemented both `MessageProducer` and `MessageSource`.
The `MessageProducer` is really redundant and confused stuff here.
From other side it might produce some side-effects from JavaConfig.

Provide some other simple but important fix for all `AbstractMessageSource` implementation to get deal with `super.afterPropertiesSet()`