* Fix unused import in the `IntegrationRequestMappingHandlerMapping`
* Fix deprecations from Reactor
* Fix race condition in the `AbstractCorrelatingMessageHandlerTests`:
the discard message is sent much earlier than group is removed from the store.
Iterate group count call until it pass or 10 seconds timeout
* Remove list size assert in the `FtpServerOutboundTests`: looks like
it is not updated properly even if we have an expected content in the collection
* Increase timeout to assert remote files removal in the `FtpRemoteFileTemplateTests`
5bac9bf66e