Merge branch 'stale-read-create-element' into 'master'

Fix stale read for existing zones on CreateElement

See merge request !1056

arkindex/documents/serializers/elements.py

@@ -399,10 +399,15 @@ class ElementCreateSerializer(ElementLightSerializer):
             # - use .only('id') to load only the id
             #   This works because of the unique constraint on image_id + polygon
             try:
-                zone = Zone.objects.filter(
-                    image_id=image.id,
-                    polygon=polygon
-                ).only('id').get()
+                zone = Zone \
+                    .objects \
+                    .using('default') \
+                    .filter(
+                        image_id=image.id,
+                        polygon=polygon
+                    ) \
+                    .only('id') \
+                    .get()
             except Zone.DoesNotExist:
                 zone = image.zones.create(polygon=polygon)