Ensure --auth-nocache is handled during renegotiation

Ensure --auth-nocache is handled during renegotiation

Currently, clearing auth_user_pass struct is delayed until
push-reply processing to support auth-token. This results in
username/password not purged after renegotiations that may
not accompany any pushed tokens -- say, when auth-token is not
in use.

Fix by always clearing auth_user_pass soon after it is used,
instead of delaying the purge as in pre-token days. But, when
"pull" is true, retain the username in auth_token in anticipation
of a token that may or may not arrive later.

Remove ssl_clean_user_pass() as there is no delayed purge any
longer -- auth-nocache handling is now done immediately after
writing username/password to the send-buffer.

Signed-off-by: Selva Nair <selva.nair@gmail.com>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20221023195105.31714-1-selva.nair@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25452.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>