changed old subject type to gradesubject

filcnaplo_kreta_api/lib/models/group_average.dart

@@ -3,7 +3,7 @@ import 'package:filcnaplo_kreta_api/models/subject.dart';
 class GroupAverage {
   String uid;
   double average;
-  Subject subject;
+  GradeSubject subject;
   Map json;
 
   GroupAverage({required this.uid, required this.average, required this.subject, this.json = const {}});
@@ -12,7 +12,7 @@ class GroupAverage {
     return GroupAverage(
       uid: json["Uid"] ?? "",
       average: json["OsztalyCsoportAtlag"] ?? 0,
-      subject: Subject.fromJson(json["Tantargy"] ?? {}),
+      subject: GradeSubject.fromJson(json["Tantargy"] ?? {}),
       json: json,
     );
   }