Merge #1204 (update django-constance to 2.9.1)

Author: martey

requirements/production.txt

@@ -3,7 +3,7 @@ django==3.2.15
 django-analytical==3.1.0
 django-anymail[postmark]==8.6
 django-autoslug==1.9.8
-django-constance[redis]==2.9.0
+django-constance[redis]==2.9.1
 django-crispy-forms==1.14.0
 django-model-utils==4.2.0
 django-multiselectfield==0.1.12