title: ScrollView "bug" on iOS 10, swift 4
body: <p>I have a problem with <code>scrollView</code>.
  As you can see in the picture, the scrolling part ends about 50 px under the <code>navigationBar</code>, however, the <code>scrollView</code> ends right under the <code>navBar</code></p>
  
  <p><a href="https://i.stack.imgur.com/TLpDW.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TLpDW.png" alt="iOS 10"></a></p>
  
  <p>On iOS 11 it works how it should as you can see in this screenshot:</p>
  
  <p><a href="https://i.stack.imgur.com/gvQMa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gvQMa.png" alt="iOS 11"></a></p>
  
  <p>As for the constraints, here is a screenshot of them.</p>
  
  <p><a href="https://i.stack.imgur.com/BsYvk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/BsYvk.png" alt="RoundedView constraints"></a></p>
  
  <p>Superview is scrollView and ScrollView is centered X and Y in the main View + top, bottom, left and right.</p>
  
  <p>Do you know what the problem might be?
  Any help much appreciated!</p>