Suppress warnings about SKStoreReviewController availability

Author: arashpayan

Appirater.m

@@ -278,7 +278,10 @@ - (void)showRatingAlert:(BOOL)displayRateLaterButton {
       return;
   }
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability"
     if (NSStringFromClass([SKStoreReviewController class]) != nil) {
+#pragma clang diagnostic pop
         [Appirater rateApp];
     } else {
         // Otherwise show a custom Alert
@@ -669,9 +672,12 @@ + (void)rateApp {
     [userDefaults setBool:YES forKey:kAppiraterRatedCurrentVersion];
     [userDefaults synchronize];
 
-  //Use the built SKStoreReviewController if available (available from iOS 10.3 upwards)
+    // Use the built SKStoreReviewController if available (available from iOS 10.3 upwards)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability"
     if (NSStringFromClass([SKStoreReviewController class]) != nil) {
         [SKStoreReviewController requestReview];
+#pragma clang diagnostic pop
         return;
     }