NegTokenInit2 Variation for Server-Initiation

Standard GSS has a strict notion of client (initiator) and server (acceptor). If the client is not waiting for a response from the server from a sent negTokenInit ([RFC4178] section 4.2.1) and the client receives a NegTokenInit2 (section 2.2.1) message from a server, the client SHOULD process messages for the received token.