Fix client user agent update on reconnect

- Fix rustdesk_id retrieval for GET requests in /updates endpoint
- Ensure user agent is properly updated when clients reconnect
- Previously, GET requests defaulted to 'unknown' rustdesk_id, preventing proper client identification

app/api/routes.py

@@ -610,6 +610,9 @@ def api_get_updates():
         
         # Track client activity if using API token
         if api_token:
+            if request.method == 'GET':
+                rustdesk_id = request.args.get('rustdesk_id')
+            else:  # POST
                 data = request.get_json() or {}
                 rustdesk_id = data.get('rustdesk_id')
             track_client_activity(api_token, rustdesk_id)