title: UIStackView seems to stack spacing even when arranged subviews are hidden
body: <p>I have 5 elements in my horizontal stack view. At one point, I hide elements at index 1 and 2. I have a spacing of 1pt and it seems that when element 1 and 2 are hidden the spacing between element 0 and 3 is the sum of the spacing between element 0 and 1, 1 and 2, and 2 and 3.
  My stack view properties are:</p>
  
  <pre><code>stackView.axis = .horizontal
  stackView.distribution = .fillEqually
  stackView.spacing = 1pt
  </code></pre>
  
  <p>My question is: How can I remove the sum of those spacings. It should not behave like this in my opinion. So am I missing something?</p>