Update spork key valid time
Update spork key valid time

Clients lost sync due to signature verification issues on testnet using the old settings.

Rejecting the old key after the fork reduces the chance of old clients forking off before the actual fork

ionomy/ion,ionomy/ion,cevap/ion,ionomy/ion,cevap/ion,cevap/ion,cevap/ion,cevap/ion,ionomy/ion,cevap/ion,ionomy/ion,ionomy/ion