find a bug ,when process nullable(DateTime) fields

[chenhunhun]

Description

find a bug ,when process nullable(DateTime) fields

public override void NullableValuesFromConst(IEnumerable objects) => Data = objects.Cast<DateTime?>().Select(x => x.GetValueOrDefault()).ToArray();

when the IEnumerable objects have some datatime, some null value, NullableValuesFromConst will raise error

在 System.Linq.Enumerable.d__971.MoveNext() 在 System.Linq.Enumerable.WhereSelectEnumerableIterator2.MoveNext()
在 System.Linq.Buffer1..ctor(IEnumerable1 source)
在 System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
在 ClickHouse.Ado.Impl.ColumnTypes.DateColumnType.NullableValuesFromConst(IEnumerable objects) 位置 C:\Users\Administrator\Desktop\ClickHouse-Net-master (1)\ClickHouse-Net-master\ClickHouse.Ado\Impl\ColumnTypes\DateColumnType.cs:行号 65
在 ClickHouse.Ado.Impl.ColumnTypes.NullableColumnType.ValuesFromConst(IEnumerable objects) 位置 C:\Users\Administrator\Desktop\ClickHouse-Net-master (1)\ClickHouse-Net-master\ClickHouse.Ado\Impl\ColumnTypes\NullableColumnType.cs:行号 70