title: UINavigation bar not getting cleared in swift3 Xcode
body: <p>I am trying to achieve a transparent navigation bar such that the background image is shown clearly. Currently i have used a base controller class where i have put a code for transparent navigation bar:</p>
  
  <pre><code> self.navigationController?.navigationBar.setBackgroundImage(UIImage(), for: .default)
  self.navigationController?.navigationBar.shadowImage = UIImage()
  self.navigationController?.navigationBar.isTranslucent = true
  self.navigationController?.view.backgroundColor = .clear
  </code></pre>
  
  <p>But currently i am getting the clear navigation bar only on first page. If i push and go to the second controller i can see a empty white space.
  See the below images:</p>
  
  <p><a href="https://i.stack.imgur.com/6gIK9.png" rel="nofollow noreferrer">First page with cleared navigation bar</a></p>
  
  <p><a href="https://i.stack.imgur.com/tQTWs.png" rel="nofollow noreferrer">Second page with empty white space at the top</a></p>
  
  <p>Why the navigation bar is not getting transparent? Any ideas?</p>