title: SWRevealViewController segue get stuck only with 1 button
body: <p>I've created an app in which I need to log-in in 2 ways:
  - Facebook Login,
  - Normal Login (email, password).</p>
  
  <p>I've added FBLogin with Facebook SDK and modified a button in order to not use fb default button. I've added a segue (Present Modally) from my loginView to anotherView with a segue (called "fb_login") and set segue class to "SWRevealViewControllerSeguePushController".</p>
  
  <p>Now, I've do the same thing with my LogIn button. changed identifier and set segue class, but when i push it my app get stuck (with no error on xCode) so I need to close it and reopen it. </p>
  
  <p>I've tried to change segue type from "Preset Modally" to "reveal view Controller set controller", but nothing changed (it don't get stuck, but it doesn't work).</p>
  
  <p>This is the function on Login button pressed:</p>
  
  <pre><code>@IBAction func loginButtonPressed(_ sender: UIButton) {
      var email = emailTextField.text
      var password = passwordTextField.text
      let urlString = "..."
  
      let urlwithPercentEscapes = urlString.addingPercentEncoding( withAllowedCharacters: .urlQueryAllowed)
  
  
      let url = URL(string: urlwithPercentEscapes!)
      URLSession.shared.dataTask(with:url!, completionHandler: {(data, response, error) in
          if error != nil {
              print(error)
          } else {
              do {
                  //PARSEDDATA CONTIENE TUTTE LE TUPLE
                  let parsedData = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as! NSDictionary
                  let temp = parsedData["user"] as! NSArray
                  var userLogin = temp[0] as! NSDictionary
                  if((userLogin["login"]) as! Int == 1){ //login successfully
                      self.user.name = userLogin["name"]! as! String
                      self.user.surname = userLogin["surname"]! as! String
                      self.user.email = userLogin["email"]! as! String
                      self.user.url_image = userLogin["profile_img_url"]! as! String
                      self.user.id_user = Int(userLogin["id_user"]! as! String)!
                      self.user.gender = Int(userLogin["gender"]! as! String)!
                      self.user.birthday = userLogin["birthday"]! as! String
                      self.user.id_license = userLogin["id_license"]! as! String
                      self.user.registration_date = userLogin["registration_date"]! as! String
                      self.user.expire_date = userLogin["expire_date"]! as! String
                      self.user.mac_address = userLogin["mac_address"]! as! String
                      self.user.license_key = userLogin["license_key"]! as! String
                      self.user.license_type = Int(userLogin["license_type"]! as! String)!
                      sleep(2)
                      self.performSegue(withIdentifier: "normal_login", sender: nil)
                  }else{ //login failed
                      print("login failed")
                  }
  
  
              } catch let error as NSError {
                  print(error)
              }
          }
  
      }).resume()
  }
  </code></pre>
  
  <p>thank you all guys! (I'm using Swift 3.0)</p>