devel/datovka: update to 4.22.1

While here move to mail category. It was wrongly placed under devel in PR 267597

ChangeLog: https://gitlab.nic.cz/datovka/datovka/-/blob/develop/ChangeLog

 * Viewing number of recently unread messages in top node description when top
   node collapsed in account list. Also changed the icon for the top node.

PR:		271005 267597
Reported by:	000.fbsd@quip.cz
Approved by:	freebsd@sysctl.cz (maintainer)