message: Fix cluster field serialization for consumer info
diff: @@ -169,6 +169,7 @@ pub struct Info {
  /// The number of pending
  pub num_pending: u64,
  /// Information about the consumer's cluster
  + #[serde(default)]
  pub cluster: ClusterInfo,
  /// Indicates if any client is connected and receiving messages from a push consumer
  #[serde(default)]
  