message: prevent locking from two places
diff: @@ -206,10 +206,11 @@ impl RefreshableToken {
  }
  RefreshableToken::File(token_file) => {
  - if let Some(token) = token_file.lock().await.cached_token() {
  + let mut locked = token_file.lock().await;
  + if let Some(token) = locked.cached_token() {
  bearer_header(token)
  } else {
  - bearer_header(token_file.lock().await.token())
  + bearer_header(locked.token())
  }
  }
  