title: Laravel 5.3 LoginController - Header may not contain more than a single header, new line detected
body: <p>I have a problem when changing the default <code>LoginController</code> redirect after login, I'm getting an 
  <code>ErrorException in Response.php line 339:
  Header may not contain more than a single header, new line detected</code></p>
  
  <p>I have already tried everything but it just does not work, the code is:</p>
  
  <pre><code>class LoginController extends Controller
  {
  
  protected $redirectTo = '/home';
  
  protected function redirectTo()
  {
      if (\Auth::check()) {
         $user_id = \Auth::id();
         $usuario = users::where('id','=',$user_id)-&gt;first();
         if($usuario-&gt;hasRole('copy')){
             return redirect('/copy/dashboardCopy');
          }
      } 
  }
  
  /**
   * Create a new controller instance.
   *
   * @return void
   */
  public function __construct()
  {
      $this-&gt;middleware('guest', ['except' =&gt; 'logout']);
  }
  }
  </code></pre>
  
  <p>According to Laravel documentation, the method has higher priority than the attribute, so I assume it's okay to leave the class attribute as it is.</p>
  
  <p>And also, I have already checked, and the code is actually reaching the last condition.</p>