Update authentik.md

I deleted the port number in the url section of the widget. When kept, the API throws an error but when removed, it works.

docs/widgets/services/authentik.md

@@ -20,6 +20,6 @@ Allowed fields: `["users", "loginsLast24H", "failedLoginsLast24H"]`.
 ```yaml
 widget:
   type: authentik
-  url: http://authentik.host.or.ip:22070
+  url: http://authentik.host.or.ip
   key: api_token
 ```