Removed dead code (caught by Clang's static analyzer).

src/video/uikit/SDL_uikitappdelegate.m

@@ -333,7 +333,6 @@ SDL_LoadLaunchImageNamed(NSString *name, int screenh)
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
 {
     NSBundle *bundle = [NSBundle mainBundle];
-    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];
 
 #if SDL_IPHONE_LAUNCHSCREEN
     /* The normal launch screen is displayed until didFinishLaunching returns,