Small opt when prune messages (paritytech#1389)

* Small opt when prune messages

* Fix typing error

bridges/modules/messages/src/outbound_lane.rs

@@ -148,19 +148,17 @@ impl<S: OutboundLaneStorage> OutboundLane<S> {
  /// Returns number of pruned messages.
  pub fn prune_messages(&mut self, max_messages_to_prune: MessageNonce) -> MessageNonce {
  let mut pruned_messages = 0;
- let mut anything_changed = false;
  let mut data = self.storage.data();
  while pruned_messages < max_messages_to_prune &&
  data.oldest_unpruned_nonce <= data.latest_received_nonce
  {
  self.storage.remove_message(&data.oldest_unpruned_nonce);
 
- anything_changed = true;
  pruned_messages += 1;
  data.oldest_unpruned_nonce += 1;
  }
 
- if anything_changed {
+ if pruned_messages > 0 {
  self.storage.set_data(data);
  }