message: Add missing comment on `filter_count` in fast sync operations
diff: @@ -73,6 +73,7 @@ struct ChainSyncContext<'a> {
  metrics: &'a Metrics,
  /// A list of peers which should be asked for data in the near future.
  bad_peer_list: RwLock<VecDeque<NodeId>>,
  + /// Number of times peer lists have been filtered.
  filter_count: AtomicI64,
  }
  