dnssec: bugfix: key rollovers timing according to real TTLs
It's necessary to save the DNSKEY TTL and zone maximal TTL at the time of previous rollover step, so that the next step corresponds with TTLs in resolvers' caches.
It's necessary to save the DNSKEY TTL and zone maximal TTL at the time of previous rollover step, so that the next step corresponds with TTLs in resolvers' caches.