INT-3431: Fix `RecipientListRouter.onInit()`

JIRA: https://jira.spring.io/browse/INT-3431

The introduced `late channel resolution by name` via https://jira.spring.io/browse/INT-3324
has lost `onInit()` propagation from `RecipientListRouter.onInit()`
So, since there is no so much changes on that 4.0.x PR, let's close this PR and cherry-pick that one.