[Dovecot] Add, but disable auth_debug

data/conf/dovecot/dovecot.conf

@@ -3,6 +3,7 @@
 # --------------------------------------------------------------------------
 auth_mechanisms = plain login
 #mail_debug = yes
+#auth_debug = yes
 log_path = syslog
 disable_plaintext_auth = yes
 # Uncomment on NFS share