message: Fix remove_expired comment.
diff: @@ -35,7 +35,7 @@ impl<I, C: Context> Default for PendingVertices<I, C> {
  }
  impl<I: NodeIdT, C: Context> PendingVertices<I, C> {
  - /// Removes expired vertices and returns `true` if it is now empty.
  + /// Removes expired vertices.
  fn remove_expired(&mut self, oldest: Timestamp) {
  for time_by_sender in self.0.values_mut() {
  time_by_sender.retain(|_, time_received| *time_received >= oldest);
  