Fix gallery parser to accept count as a string to be parsed not int

lib/serializers/friendica/gallery_data_friendica_extensions.dart

@@ -2,7 +2,7 @@ import '../../models/gallery_data.dart';
 
 extension GalleryDataFriendicaExtensions on GalleryData {
   static GalleryData fromJson(Map<String, dynamic> json) => GalleryData(
-      count: json['count'] ?? -1,
+      count: int.tryParse(json['count']) ?? -1,
       name: json['name'] ?? 'Unknown',
       created: DateTime.tryParse(json['created']) ?? DateTime(0));
 }