message: Fix bug with Consumer::pull_opt where deliver_subject was not properly tested
diff: @@ -1004,11 +1004,11 @@ impl Consumer {
  ));
  }
  - if self.cfg.deliver_subject.is_none() {
  + if self.cfg.deliver_subject.is_some() {
  return Err(Error::new(
  ErrorKind::InvalidInput,
  "this method is only usable from \
  - Pull-based Consumers with a deliver_subject set",
  + Pull-based Consumers with a deliver_subject set to None",
  ));
  }
  