fix reference in tests

Author: kentico-ericd

test/Kentico.Xperience.Contacts.Importer.Generator/Program.cs

@@ -6,7 +6,7 @@
 
 using Kentico.Xperience.Contacts.Importer.Generator;
 
-using static Kentico.Xperience.Contacts.Importer.Services.ImportService;
+using static Kentico.Xperience.Contacts.Importer.Services.ImportService.ImportService;
 
 string? solutionFolder = FindSolutionFolder();