Django fixup should close all cache backends (celery#4187)

Author: raphael-riel

celery/fixups/django.py

@@ -193,7 +193,7 @@ def _close_database(self):
 
     def close_cache(self):
         try:
-            self._cache.cache.close()
+            self._cache.close_caches()
         except (TypeError, AttributeError):
             pass
 

t/unit/fixups/test_django.py

@@ -227,9 +227,7 @@ def test__close_database(self):
     def test_close_cache(self):
         with self.fixup_context(self.app) as (f, _, _):
             f.close_cache()
-            f._cache.cache.close.assert_called_with()
-            f._cache.cache.close.side_effect = TypeError()
-            f.close_cache()
+            f._cache.close_caches.assert_called_with()
 
     def test_on_worker_ready(self):
         with self.fixup_context(self.app) as (f, _, _):