Move misplaced using directive

Author: alex-kulakov

Orm/Xtensive.Orm/IoC/ServiceContainer.cs

@@ -16,11 +16,10 @@
 using AttributeSearchOptions = Xtensive.Reflection.AttributeSearchOptions;
 using AppConfiguration = System.Configuration.Configuration;
 using ConfigurationSection = Xtensive.IoC.Configuration.ConfigurationSection;
+using Key = System.ValueTuple<System.Type, string>;
 
 namespace Xtensive.IoC
 {
-  using Key = ValueTuple<Type, string>;
-
   /// <summary>
   /// Default IoC (inversion of control) container implementation.
   /// </summary>