message: Use impl AsRef rather than a generic parameter
  I could have sworn that I fixed this already
diff: @@ -1406,11 +1406,8 @@ impl Connection {
  }
  /// Close the connection.
  - pub fn close<S>(&mut self, now: Instant, error: AppError, msg: S)
  - where
  - S: AsRef<str>,
  - {
  - let msg: &[u8] = msg.as_ref().as_ref();
  + pub fn close(&mut self, now: Instant, error: AppError, msg: impl AsRef<str>) {
  + let msg = msg.as_ref().as_bytes();
  self.set_state(State::Closing {
  error: ConnectionError::Application(error),
  frame_type: 0,
  