message: Fix failed with_refresh_token_example
diff: @@ -66,13 +66,17 @@ async fn main() {
  .prompt_for_token(&url)
  .await
  .expect("couldn't authenticate successfully");
  + // Token refreshing works as well, but should with the one generated in the
  + // previous request
  + let prev_token = spotify.get_token().lock().await.unwrap().clone();
  do_things(spotify).await;
  // At a different time, the refresh token can be used to refresh an access
  // token directly and run requests:
  println!(">>> Session two, running some requests:");
  let spotify = AuthCodeSpotify::new(creds.clone(), oauth.clone());
  - // No `prompt_for_user_token_without_cache` needed.
  + *spotify.token.lock().await.unwrap() = prev_token.clone();
  + // No `prompt_for_user_token` needed.
  spotify
  .refresh_token()
  .await
  @@ -83,6 +87,7 @@ async fn main() {
  // refresh token that was obtained at the beginning.
  println!(">>> Session three, running some requests:");
  let spotify = AuthCodeSpotify::new(creds, oauth);
  + *spotify.token.lock().await.unwrap() = prev_token;
  spotify
  .refresh_token()
  .await
  