Fix absence creation

aleksis/apps/untis/util/mysql/importers/absences.py

@@ -108,20 +108,22 @@ def import_absences(
             room = rooms_ref[absence.ida]  # noqa
 
         if teacher:
-            defaults = {
-                "reason": reason,
-                "person": teacher,
-                "datetime_start": datetime_start,
-                "datetime_end": datetime_end,
-                "comment": comment,
-            }
-
-            new_absence, created = kolego_models.Absence.objects.update_or_create(
-                extended_data__import_ref_untis=import_ref, defaults=defaults
-            )
-
+            try:
+                created = False
+                new_absence = kolego_models.Absence.objects.get(
+                    extended_data__import_ref_untis=import_ref
+                )
+            except kolego_models.Absence.DoesNotExist:
+                created = True
+                new_absence = kolego_models.Absence()
+
+            new_absence.reason = reason
+            new_absence.person = teacher
+            new_absence.datetime_start = datetime_start
+            new_absence.datetime_end = datetime_end
+            new_absence.comment = comment
             new_absence.extended_data["import_ref_untis"] = import_ref
-            new_absence.save()
+            new_absence.save(skip_overlap_handling=True)
 
             if created:
                 logger.info("  New absence created")