Update Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlMetadata.cs

Co-authored-by: Alexey Kulakov <alexey.kulakov@dataobjects.net>

Author: SergeiPavlov

Orm/Xtensive.Orm/Sql/Dml/Expressions/SqlMetadata.cs

@@ -1,3 +1,7 @@
+// Copyright (C) 2022 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
 using Xtensive.Core;
 
 namespace Xtensive.Sql.Dml