The option `update-check-ksk` will look if both KSK and ZSK are
available before signing records. It will make sure the keys are
active and available. However, for operational practices keys may
be offline. This commit relaxes the update-check-ksk check and will
mark a key that is offline to be available when adding signature
tasks.
(cherry picked from commit 3cb8c49c73)
f4dc62f33b