[Dovecot] imap login messages not logged

[Nikolay Shopik]

One of my server stop logging such messages when user trying to login.
imap-login: Login: user=<username at example.com>.
I check configuration from another server and it very same.

I'm running on debian testing with config below.
# 1.0.5: /etc/dovecot/dovecot.conf
log_path: /var/log/dovecot.log
info_log_path: /var/log/dovecot.info
protocols: imap
ssl_cert_file: /etc/postfix/new_chained.crt
ssl_key_file: /etc/postfix/mail.pem
login_dir: /var/run/dovecot/login
login_executable: /usr/lib/dovecot/imap-login
login_greeting_capability: yes
mail_location: maildir:/var/mail/store/%u
dotlock_use_excl: yes
maildir_copy_with_hardlinks: yes
auth default:
  mechanisms: PLAIN CRAM-MD5
  passdb:
    driver: passwd-file
    args: /etc/dovecot/passwd
  userdb:
    driver: static
    args: uid=vmail gid=vmail home=/var/mail/store/%u
  socket:
    type: listen
    client:
      path: /var/spool/postfix/private/auth
      mode: 432
      user: postfix
      group: postfix
    master:
      path: /var/run/dovecot/auth-master
      mode: 438
      user: root
      group: root
plugin:
  sieve: /var/mail/store/%u/sieve