Make the "ask qnet" language even more clear/alarmist

Somehow, new users on Vertrauen *still* manage to answer "Yes" to both the QWK
Networking account questions, accidentally creating a QWKnet account that's
not useful for normal BBS user activities. So print a very clear "alert" style
message making it even-more clear that the account they are creating will ONLY
be useful for QWK Networking activities.