title: load url image using kingfisher freeze when scrolling fast
body: <p>I have a horizontal collection view inside tableview</p>
  
  <p>In each collection view there are no of images loading from url with kingfisher library</p>
  
  <p>but when i scroll fast ,tableview freeze for some seconds &amp; scrolling continue after display cells images loading completed</p>
  
  <p>I'm using UICollectionViewCell xib for cell reuse</p>
  
  <pre><code>self.imgPhoto.kf.setImage(with: URL(string: varImageURL))
  </code></pre>