Fix build

Author: SergeiPavlov

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

@@ -1039,7 +1039,7 @@ private ProjectionExpression VisitGroupBy(Type returnType, Expression source, La
               ExpressionType.AndAlso);
           });
 
-      var filter = FastExpression.Lambda(filterBody, tupleParameter);
+      var filter = FastExpression.Lambda(filterBody, TupleParameter);
       var subqueryProjection = sequence.Apply(new ItemProjectorExpression(
           sequence.ItemProjector.Item,
           groupingSourceProjection.ItemProjector.DataSource.Filter((Expression<Func<Tuple, bool>>) filter),