Fix bug in translator

Author: SergeiPavlov

Orm/Xtensive.Orm/Orm/Linq/Translator.Queryable.cs

@@ -1292,7 +1292,8 @@ private ProjectionExpression VisitSelectMany(Expression source, LambdaExpression
         var outerParameters = State.OuterParameters
           .Concat(State.Parameters)
           .Concat(collectionSelector.Parameters)
-          .Append(outerParameter).ToArray(State.Parameters.Length + collectionSelector.Parameters.Count + 1);
+          .Append(outerParameter)
+          .ToArray(State.OuterParameters.Length + State.Parameters.Length + collectionSelector.Parameters.Count + 1);
         using (CreateScope(new TranslatorState(State) {
           OuterParameters = outerParameters,
           Parameters = Array.Empty<ParameterExpression>(),