Fix insert expression timespan property

if you do a migration like this:
```C#
            Create.Table("TimeRanges")
                .InSchema(MigrationVersionMeta.DefaultSchemaName)
                .WithColumn("ID").AsInt32().Identity().PrimaryKey()
                .WithColumn("Description").AsString(50).Nullable()
                .WithColumn("From").AsTime().NotNullable()
                .WithColumn("To").AsTime().NotNullable()
                .WithColumn("Order").AsInt32().NotNullable().WithDefaultValue(0);

            Insert.IntoTable("TimeRanges")
                .InSchema(MigrationVersionMeta.DefaultSchemaName)
                .Row(new { Description = "00-05", From = TimeSpan.Zero, To = new TimeSpan(0, 5, 59, 59, 999), Order = 0 })
                .Row(new { Description = "06-09", From = new TimeSpan(0, 6, 00, 0, 0), To = new TimeSpan(0, 9, 59, 59, 999), Order = 1 })
                ;
```

The migration fails.