title: self.navigationController? is nil when pushing from a objective-c viewController to a Swift ViewController
body: <p>I'm trying to show the ToolBar of the navigationcontroller after pushing from a Objective C Class to a Swift Class by using this code, but the toolbar is not shown:</p>
  
  <pre><code>self.navigationController?.setToolbarHidden(false, animated: false)
  </code></pre>
  
  <p>Then I did a print of self.navigationController? and it returned nil.</p>
  
  <p>If I go from Obj-C to Obj-C the navigationController is found.</p>
  
  <p>Any solutions?</p>