Loading Storyboard from AppDelegate leaves black space on window

I am launching Storyboard from AppDelegate but getting black space on top and bottom of screen. Here is my code :

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.

    [[UINavigationBar appearance] setTitleTextAttributes:@{NSForegroundColorAttributeName: [UIColor whiteColor]}];
    [[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]];
    UIViewController *vc =[storyboard instantiateInitialViewController];

    // Set root view controller and make windows visible
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.rootViewController = vc;
    [self.window makeKeyAndVisible];

    return YES;
}  

Here is what it looks like :