Set annotation id to "Migration" for Migration Errors.

PROMS/DataLoader/Steps.cs

@@ -216,6 +216,7 @@ namespace DataLoader
 					{
 						ItemAnnotation ia = item.ItemAnnotations.Add(MigrationErrorType);
 						ia.SearchText = str;
+						ia.UserID = "Migration";
 					}
 					if (!item.IsSavable) ErrorRpt.ErrorReport(item);
 					item.Save();