"Fixed" the bug by adding a default-handler

"Fixed" the bug by adding a default-handler

* The default-handler is _NOT_ necessary, if the handler-methods only
  consume the message itself.
* This looks like a bug in the automatic configuration:
  * Without the addtional parameter of type `ConsumerRecordMetaData`, the
    automatically created resolvers are able to consume the payload.
  * After the addition of the `consumerRecordMetaData`-parameter, the
    automatically created resolvers are empty and fail to resolve the
    payload.
  * After the addition of the default-handler, the required resolvers
    are availabe again.