OIDC list accounts (#994)

Added the function to use lists instead of a single string in account autoprovision.

powerdnsadmin/models/setting.py

@@ -28,6 +28,7 @@ class Setting(db.Model):
         'allow_user_create_domain': False,
         'allow_user_remove_domain': False,
         'allow_user_view_history': False,
+	'delete_sso_accounts': False,
         'bg_domain_updates': False,
         'enable_api_rr_history': True,
         'site_name': 'PowerDNS-Admin',