title: How to change UITableViewCell Image to Circle in UITableView
body: <p>My code works for the most part.</p>
  <ul>
  <li>The issue I am having is the images start out as square, and change to circle when I scroll the table or refresh it.</li>
  </ul>
  <p>What am I missing?</p>
  <p><strong>Here's my code:</strong></p>
  <pre><code>    cell.imageView.layer.cornerRadius = cell.imageView.frame.size.width / 2.0;
      cell.imageView.layer.borderWidth = 3.0;
      cell.imageView.layer.borderColor = [UIColor colorWithRed:157.0/255.0 green:34.0/255.0 blue:53.0/255.0 alpha:1.0]
      .CGColor;
      cell.imageView.clipsToBounds = YES;
  
      NSDictionary *tweet = (self.results)[indexPath.row];
      
      dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
      dispatch_async(queue, ^{
      
          NSString * imageString = [tweet valueForKeyPath:@&quot;user.profile_image_url&quot;];
          NSData * imageData = [[NSData alloc] initWithContentsOfURL: [NSURL URLWithString:imageString]];
          
          if (imageData != nil)
          {
              dispatch_async(dispatch_get_main_queue(), ^{
                  
                  cell.imageView.image = [UIImage imageWithData: imageData];
  
                  [cell setNeedsLayout];
              });
          }
      });
  </code></pre>
  <p><strong>EDIT</strong> ---- The code is in <code>cellForRowAtIndexPath</code></p>
  <ul>
  <li>Right when I launch the app the cell images are square. If I <code>pullToRefresh</code> the change to round or if I start scrolling the table they change to round.</li>
  </ul>
  <p><strong>EDIT TWO</strong></p>
  <p>Another issue I am seeing is the images change as I scroll.</p>
  <p>How do I prevent this?</p>