Merge pull request #941 from OneSignal/fix/fixing_nullability_of_content_block

fixing content handler block nullability

Author: emawby

iOS_SDK/OneSignalSDK/Source/OneSignal.h

@@ -489,7 +489,7 @@ typedef void (^OSInAppMessageClickBlock)(OSInAppMessageAction * _Nonnull action)
 // Process from Notification Service Extension.
 // Used for iOS Media Attachemtns and Action Buttons.
 + (UNMutableNotificationContent*)didReceiveNotificationExtensionRequest:(UNNotificationRequest* _Nonnull)request withMutableNotificationContent:(UNMutableNotificationContent* _Nullable)replacementContent __deprecated_msg("Please use didReceiveNotificationExtensionRequest:withMutableNotificationContent:withContentHandler: instead.");
-+ (UNMutableNotificationContent*)didReceiveNotificationExtensionRequest:(UNNotificationRequest* _Nonnull)request withMutableNotificationContent:(UNMutableNotificationContent* _Nullable)replacementContent withContentHandler:(void (^)(UNNotificationContent * _Nullable))contentHandler;
++ (UNMutableNotificationContent*)didReceiveNotificationExtensionRequest:(UNNotificationRequest* _Nonnull)request withMutableNotificationContent:(UNMutableNotificationContent* _Nullable)replacementContent withContentHandler:(void (^)(UNNotificationContent *_Nonnull))contentHandler;
 + (UNMutableNotificationContent*)serviceExtensionTimeWillExpireRequest:(UNNotificationRequest* _Nonnull)request withMutableNotificationContent:(UNMutableNotificationContent* _Nullable)replacementContent;
 
 #pragma mark Tags