Dtos: Fix error when given_name is null

Elwig/Models/Dtos/OverUnderDeliveryData.cs

@@ -53,7 +53,7 @@ namespace Elwig.Models.Dtos {
         [Column("name_1")]
         public required string Name1 { get; set; }
         [Column("name_2")]
-        public required string Name2 { get; set; }
+        public string? Name2 { get; set; }
         [Column("address")]
         public required string Address { get; set; }
         [Column("plz")]