title: Strange white space at UITableView header when using UISearchController with UITableViewController on iOS 10
body: <p>The white space only appears on iOS 10.</p>
  
  <p><a href="https://i.stack.imgur.com/Iem7T.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Iem7T.png" alt="iOS10HeaderBug"></a></p>