In #68757, v3 instead of v4 of the patchset was committed by accident.
This patch revives the (minor) changes made in the v4.
* gnu/service/dns.scm: Remove exports of no longer existing names.
(unbound-service-type): Fix at typo (unbound -> Unbound).
(unbound-shepherd-service): Run after user processes.
(unbound-account-service): Determine shell based on shadow package.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>