Gnus parses authinfo even if no server require that

[XeCycle]

I recently have my ~/.authinfo GPG-encrypted, and Gnus keeps
asking me to decrypt that on startup.  But none of my select
methods require authentication --- one is nnml, which I
apparently didn't encrypt; another is leafnode local server, nor
does it require authentication.

Wondering what's wrong here, I set nntp-authinfo-file for
localhost to "/dev/null", but it still asks me for a password.

The authinfo file contains only one line, used to send my mail.

Like a bug?

gnus-version "Ma Gnus v0.4"

-- 
Carl Lei (XeCycle)
Department of Physics, Shanghai Jiao Tong University
OpenPGP public key: 7795E591
Fingerprint: 1FB6 7F1F D45D F681 C845 27F7 8D71 8EC4 7795 E591

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