gssapi considered as PLAIN?

[Harry Schmalzbauer]

 Hello,

as soon as I set "disable_plaintext_auth = yes", AUTH=GSSAPI vanishes
from capabilities.
([CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE
STARTTLS AUTH=GSSAPI AUTH=PLAIN AUTH=LOGIN] vs [CAPABILITY IMAP4rev1
LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS LOGINDISABLED])

Why?
I'm wondering especially because at
http://wiki2.dovecot.org/Authentication/Mechanisms, GSSAPI is correctly
listed under “Non-plaintext authentication“.

Thanks,

-Harry