title: iOS 11 UISearchBar: left + rightbarbuttonitem vertical center issue
body: <p>With IOS 11, I've encountered another one issue in <code>UISearchController</code>.
  As default height value became 56 <code>rightBarButtonItem</code> and <code>leftBarButtonItem</code> are staying in their old places, regardless of whether it's text or image.</p>
  
  <p>I need to centre items to the search bar as it were in IOS 10. </p>
  
  <p><a href="https://i.stack.imgur.com/iSHkb.png" rel="nofollow noreferrer">refresh buttons are not centered</a></p>
  
  <p>As you can see the item buttons are bit higher than center of searchbar.</p>
  
  <p>I tried to do: <code>[self.searchController.searchBar.heightAnchor constraintLessThanOrEqualToConstant: 44].active = YES;</code></p>
  
  <p>But I got search bar overlapping buttons: </p>
  
  <p><a href="https://i.stack.imgur.com/QO8X1.png" rel="nofollow noreferrer">searchbar overlaps buttons</a></p>
  
  <p>However, after I enter edit mode and return back by pressing Cancel - it begins to look good in case of 44 constraints.</p>
  
  <p>I also tried to play with setting <code>centerYanchor</code> to <code>imageView</code> (of button) same as in <code>searchBar</code> but had crashed.</p>