EAP-PEAP transports results as separate AVPs, we expect one after the
first phase 2 authentication (if not using certificates). However, with
the previous caching of the result of that, the client could then send
another confirmation as response to the EAP-TNC request to skip it.
Since no group membership is set if EAP-TNC is not complete, it shouldn't
really affect its outcome, though.
Fixes: 1be296dfb2 ("implemented the PEAP tunneling protocol as an EAP plugin")