In Memcached, unix time expiry before now is considered as immortal

In memcached, if lifespan is bigger than seconds in a month, it is considered unix time, but if this time is smaller than current time, a negative number is produced and passed to Infinispan cache which results in entry not being removed. Instead, Memcached server should spot this and since the time is in the past, pass 0 to remove it immediately.