Get validity ranges by Untis ID and the corresponding school term

(cherry picked from commit bfcc6f33)

CHANGELOG.rst

@@ -6,6 +6,14 @@ All notable changes to this project will be documented in this file.
 The format is based on `Keep a Changelog`_,
 and this project adheres to `Semantic Versioning`_.
 
+Unreleased
+----------
+
+Fixed
+~~~~~
+
+* Get validity ranges by Untis ID and the corresponding school term.
+
 `2.0rc1`_ - 2021-06-23
 ----------------------
 

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

@@ -104,7 +104,9 @@ def import_terms(qs: Optional[QuerySet] = None,) -> Dict[int, chronos_models.Val
         school_term.save()
 
         try:
-            validity_range = chronos_models.ValidityRange.objects.get(import_ref_untis=term_id)
+            validity_range = chronos_models.ValidityRange.objects.get(
+                import_ref_untis=term_id, school_term=school_term
+            )
             logger.info("  Validity range found by import reference.")
         except chronos_models.ValidityRange.DoesNotExist:
             try: