MailTracker - remove special case for before-queue

MailTracker - remove special case for before-queue

Since we've recently added dedicated before-queue status to pmg-log-tracker
the MailTracker should treat before and after queue filtered mail equally.

This patch drops the note stating otherwise.
Additionally the line with 'queued/delivered' was left in place, since the
status does exist (as with the other 'queued' status mails it happens for
internally generated mails).

This commit partially reverts 6abb9ee31568c3828ab83fa8ec264d90fffe7dd1

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>