AppDelegate: Use correct prototype for restorationHandler

Sources/VLCAppDelegate.m

@@ -158,7 +158,7 @@
 
 - (BOOL)application:(UIApplication *)application
 continueUserActivity:(NSUserActivity *)userActivity
- restorationHandler:(void (^)(NSArray *))restorationHandler
+ restorationHandler:(void (^)(NSArray<id<UIUserActivityRestoring>> *))restorationHandler
 {
     NSString *userActivityType = userActivity.activityType;
     NSDictionary *dict = userActivity.userInfo;