The `rndc signing -clear` command cleans up the private-type records
that keep track of zone signing activity, but before this change it
did not tell the secondary servers that the zone has changed.
(cherry picked from commit f3f7b7df5d)
The `rndc signing -clear` command cleans up the private-type records
that keep track of zone signing activity, but before this change it
did not tell the secondary servers that the zone has changed.
(cherry picked from commit f3f7b7df5d)