Update status.py

avoid error if last-login is None

backend/core/management/commands/status.py

@@ -23,7 +23,9 @@ def handle(self, *args, **kwargs):
         nb_risk_acceptances = RiskAcceptance.objects.all().count()
         created_at = Folder.get_root_folder().created_at
         last_login = max(
-            x["last_login"] for x in User.objects.all().values("last_login")
+            x["last_login"]
+            for x in User.objects.all().values("last_login")
+            if x["last_login"]
         )
         self.stdout.write(
             f"created_at={created_at.strftime('%Y-%m-%dT%H:%M')} last_login={last_login.strftime('%Y-%m-%dT%H:%M') if last_login else last_login} "