Patch cache hit if there is a change

[ckcr4lyf]

In kiryuu, if we get a cache hit on the announce reply from redis, currently we serve it as is.

However, if the announce resulted in a change (e.g. new seeder, new leecher, stopped seeding, stopped leeching) , we need to modify the complete and incomplete values in the reply.

This issue is to track this improvement, so we can return slightly better numerical values.