apps: corrige le hook event/fc-link en cas d'absence de partenaire sur la requête

src/authentic2_cut/apps.py

@@ -631,7 +631,7 @@ class AppConfig(django.apps.AppConfig):
         user.attributes.validation_date = now().date()
         partner = request.session.get('service_slug')
         if hasattr(request, 'partner'):
-            partner = partner or request.partner.get('ou_slug')
+            partner = partner or (request.partner and request.partner.get('ou_slug')):
         if partner:
             user.attributes.validation_partner = partner