518df4f74b
https://build.spring.io/browse/INT-MJATS41-573/ The latest SF changes (https://jira.spring.io/browse/SPR-14042) added a restriction (breaking change) when only `public` classes and their methods can be exposed as a managed resources and attributes, operations, respectively. * Make `NotificationPublishingMessageHandler.PublisherDelegate` as `public` according the new requirement. Even if it doesn't look necessary, because our `PublisherDelegate` is just for notification, it sounds logical that any exposed into the JMX resource won't be `private` any more.