message: Only retain non-closed subscriptions on reconnect
diff: @@ -697,6 +697,9 @@ impl ConnectionHandler {
  let (_, connection) = self.connector.connect().await?;
  self.connection = connection;
  + self.subscriptions
  + .retain(|_, subscription| !subscription.sender.is_closed());
  +
  for (sid, subscription) in &self.subscriptions {
  self.connection
  .write_op(ClientOp::Subscribe {
  