title: UIScrollview and Nav bar content offset issue
body: <p>So i am trying to get my head around how the nav bar and scroll views can work together.</p>
  
  <p>the issue i am having is when i put my label on a view controller that has a nav bar and scroll view it seems that i must put the label underneath the nav bar so it's obscured by the nav bar in order to get the right amount of offset.</p>
  
  <p>The thing is, if i click on the view controller and change the Top Bar from inferred to None and set up my views that way and then switch it back after my views are set up it seems to work, e.g. it automatically moves my content on the inteface builder to be below the nav bar and all constraints then work ok.</p>
  
  <p>I am guessing i am missing the concept here on how scroll views and nav bars are set up as surly you dont have to change it to none and then back again in order for it to correct the views?</p>
  
  <p>Edit 1: it seems that its to do with where I pin the top of the label.... if I pin it to Top Layout Guide (so it adjusts successfully for the nav bar and status bar) then it doesn't move at all, If I pin it to top of the container view I have then its set at 64pts which I don't want hardcoded?</p>
  
  <p><a href="https://i.stack.imgur.com/0sDlA.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0sDlA.jpg" alt="Scroll View with Label"></a></p>