title: "The configuration foo.bar was supplied but isn't a known config"
body: <p>When I'm starting a connector in distributed mode (connect-runtime v1.0.0), there are several configuration values that are mandatory. I'm speaking of values like:</p>
  <pre><code>offset.storage.topic
  offset.storage.partitions
  key.converter
  config.storage.topic
  config.storage.replication.factor
  rest.port
  status.storage.topic
  key.converter.schemas.enable
  value.converter.schemas.enable
  internal.value.converter
  internal.key.converter
  internal.key.converter.schemas.enable
  internal.value.converter.schemas.enable
  status.storage.partitions
  status.storage.topic
  value.converter
  offset.flush.interval.ms
  offset.storage.replication.factor
  ...
  </code></pre>
  <p>Once the connector is started with meaningful values for those properties, it works as expected. But at startup, the log get's flooded with entries like</p>
  <pre><code>WARN  o.a.k.c.admin.AdminClientConfig.logUnused - The configuration 'offset.storage.topic' was supplied but isn't a known config.
  </code></pre>
  <p>for all above mentioned, mandatory configuration values.
  There are three config classes which are logging these warnings:</p>
  <pre><code>org.apache.kafka.clients.consumer.ConsumerConfig
  org.apache.kafka.clients.admin.AdminClientConfig
  org.apache.kafka.clients.producer.ProducerConfig
  </code></pre>
  <p>Since now I haven't found a reason for this behavior. What's missing here or what is wrong, that causes this warnings? Do I have to worry about this warnings?</p>