title: Keep autolayout constraints active status on device rotation
body: <p>I noticed that when I update my autolayout constraints programmatically, all changes are reverted when I rotate the screen.</p>
  
  <p>Reproduce the issue:</p>
  
  <ul>
  <li><p>Basic Storyboard interface with UIView and 2 constraints:</p>
  
  <ol>
  <li>width equal superview.width (multiplier 1) active</li>
  <li>width equal superview.width (multiplier 1/2) disabled</li>
  </ol></li>
  <li><p>Create and link these 2 constraints with IBOutlet</p></li>
  <li>Programmatically disable the first constraint and enable the second one.</li>
  <li>Rotate the device, the first constraint is active and the second one disabled.</li>
  </ul>
  
  <p>Seems like a bug to me.</p>
  
  <p>What do you think ?</p>
  
  <p>Screenshots:</p>
  
  <p>Storyboard:
  <a href="https://i.stack.imgur.com/aFaH5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/aFaH5.png" alt="enter image description here"></a></p>
  
  <p>Constraint #1:</p>
  
  <p><a href="https://i.stack.imgur.com/hpidH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hpidH.png" alt="enter image description here"></a></p>
  
  <p>Constraint #2:</p>
  
  <p><a href="https://i.stack.imgur.com/iqvbz.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/iqvbz.png" alt="enter image description here"></a></p>