Use `fee_satoshis` when replying to quick close (as non-opener), not `max_fee_satoshis`

[rustyrussell]

fee_satoshis is the amount they suggest, so you should only respond with a different amount if it's disagreeable. max_fee_satoshis is the worst case for them, so choosing it is fairly anti-social.

The spec does not actually spell this out, unfortunately, but when combined with CLN's "YOLO ignore-fee-rates" option (which sets the feerate to 0xFFFFFFF), the result is stupidly expensive:

https://github.com/ElementsProject/lightning/issues/7242

(And yes, v3 close fixes this, but this is deployed now...)