title: Navigation right bar button image is white from url
body: <p>I'm attempting to show an image from a url in the right bar button of the navigation bar. All I'm seeing is a white image. The image loads fine in other parts of the app with the same technique. What am I doing wrong?</p>
  
  <pre><code>[[SDWebImageDownloader sharedDownloader]downloadImageWithURL:[NSURL URLWithString:self.avatarUrl] options:SDWebImageDownloaderContinueInBackground progress:^(NSInteger receivedSize, NSInteger expectedSize) {
  
  } completed:^(UIImage *image, NSData *data, NSError *error, BOOL finished) {
  
    UIBarButtonItem *avatarItem = [[UIBarButtonItem alloc] initWithImage:[Utils imageWithImage:image scaledToSize:CGSizeMake(32.0f, 32.0f)] style:UIBarButtonItemStylePlain target:self action:@selector(showUser)];
    self.navigationItem.rightBarButtonItem = avatarItem;
  
  }];
  </code></pre>