Adding compiler directive to ignore User +sharedProfileImageRequestOperationQueue in iOS

Example/Classes/Models/User.m

@@ -25,9 +25,11 @@
 
 NSString * const kUserProfileImageDidLoadNotification = @"com.alamofire.user.profile-image.loaded";
 
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
 @interface User ()
 + (NSOperationQueue *)sharedProfileImageRequestOperationQueue;
 @end
+#endif
 
 @implementation User {
 @private