title: UIViewController with UITableView and UISearchBar gap issue
body: <p>I have a <code>UIViewController</code> with a <code>UITableView</code> and a <code>UISearchBar</code> inside. As soon as the searchbar becomes first responder, there's a small gap between the searchbar and the tableview.</p>
  
  <p><img src="https://i.imgur.com/5RrRH1Y.png" alt="Initial state"><img src="https://i.stack.imgur.com/94hmP.png" alt="Searchbar becomes first responder"></p>
  
  <p>There's no gap when the <code>UISearchBar</code> is a subview of the <code>UIViewController</code> view instead of being a subview of the <code>UITableView</code>. </p>
  
  <p><img src="https://i.stack.imgur.com/8BkbA.png" alt="Initial state"><img src="https://i.stack.imgur.com/6rK8s.png" alt="Searchbar becomes first responder"></p>
  
  <p>Obviously, one issue with that approach is that the searchbar stick to the top and doesn't scroll along with other cells, which is not desired.</p>
  
  <p>Any ideas?</p>
  
  <p><strong>Edit:</strong></p>
  
  <p>Two first images correspond to the <code>UISearchBar</code> being a child of the <code>UITableView</code>, where the gap is occurring.</p>
  
  <p>Last two images correspond to the <code>UISearchBar</code> being a child of the <code>UIViewController</code> view, in which case there's no gap.</p>