title: applicationWillEnterForeground gets found nil for textLabel
body: <p>I'm trying to change text on label when app will enter foreground but I always get </p>
  
  <p>fatal error: unexpectedly found nil while unwrapping an Optional value</p>
  
  <pre><code>ViewController.swift
  
    @IBOutlet var textLabel: UILabel!
  
      func showLabel() {
          textLabel.text = "Welcome back"
      }
  </code></pre>
  
  <p>and</p>
  
  <pre><code>AppDelegate.swift
  
  func applicationWillEnterForeground(application: UIApplication) {
         ViewController().showLabel()
      }
  </code></pre>
  
  <p>Any Idea how to fix it?</p>