title: Game center login  lock in landscape only in i OS 6
body: <p>When Game center is loaded its default orientation is portrait. 
   In order to lock it in landscape mode, added a category.</p>
  
  <pre><code>@implementation GKMatchmakerViewController (LandscapeOnly)
  
  - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation 
  { 
      return ( interfaceOrientation == UIInterfaceOrientationLandscapeLeft || interfaceOrientation == UIInterfaceOrientationLandscapeRight);
  }
  
  -(NSUInteger)supportedInterfaceOrientations
  {
      return UIInterfaceOrientationMaskLandscape;
  }
  
  - (BOOL)shouldAutorotate {
      return NO;
  }
  @end
  </code></pre>
  
  <p>It is working fine in below iOS 6 .But in iOS6 it shows an error.</p>
  
  <p>Terminating app due to uncaught exception 'UIApplicationInvalidInterfaceOrientation', reason: 'Supported orientations has no common orientation with the application, and shouldAutorotate is returning YES'</p>
  
  <p>Please explain a solution.</p>