Merge pull request #841 from execut/fix-bug-with-invalidate-cache

#826 changed cache import definition

shop/models/product.py

@@ -4,7 +4,8 @@
 
 from django.apps import apps
 from django.conf import settings
-from django.core import cache, checks
+from django.core import checks
+from django.core.cache import cache
 from django.db import models
 from django.db.models.aggregates import Sum
 from django.db.models.functions import Coalesce