/**
     * Enforce secure negotiation
     * 
     * Property <tt>jcifs.smb.client.requireSecureNegotiate</tt> (boolean, default true)
     * 
     * This does not provide any actual downgrade protection if SMB1 is allowed.
     * 
     * It will also break connections with SMB2 servers that do not properly sign error responses.
     * 
     * @return whether to enforce the use of secure negotiation.