Better visiblity in ui when device config not present

Hi,

When a user is disabled or his device gets deleted, the client looses connectivity, as expected.
However from a client UI perspective, this is not really clear.
In the defguard client under locations, the state remains connected/active with a green status symbol.

In settings/log these entries are present: ```internal error: device config not present in response```
Only after 5 minutes a popup appears with the message
```The Location XXX has been disconnected, since we have detected that the server is not responding with any traffic for 300s. If this message keeps occurring, please contact your administrator and inform them about this fact.```

Is it possible to indicate this more clearly (upon connection) to the client, that the connection cannot be established?

L’issue non indica file né test; inizia tracciando lo stato di Locations e la gestione della connessione del client in relazione alla configurazione del dispositivo mancante segnalata. Il lavoro è completato quando la UI indica chiaramente che la posizione è disconnessa quando il server non fornisce una configurazione del dispositivo, invece di mantenere uno stato verde di connessione.

Scritto dal modello di indicizzazione a partire dal testo della issue.