Dtos: Fix error when given_name is null

Elwig/Models/Dtos/DeliveryJournalData.cs

@@ -58,7 +58,7 @@ namespace Elwig.Models.Dtos {
         public string DeliveryBranch;
         public int MgNr;
         public string Name1;
-        public string Name2;
+        public string? Name2;
         public string AdministrativeName;
         public string? MemberBranch;
         public string SortId;