TD-4223- passed blank last access date when a new delegate enrolled on group courses.

Author: Auldrin-Possa

DigitalLearningSolutions.Web/Services/GroupsService.cs

@@ -755,7 +755,7 @@ IEnumerable<NotificationPreference> delegateNotificationPreferences
                     delegateUserId,
                     groupCourse.CustomisationId,
                     groupCourse.CurrentVersion,
-                    clockUtility.UtcNow,
+                    null,
                     3,
                     addedByAdminId,
                     completeByDate,