Update amount.h
Update amount.h

Revert suspected conflict where upstream moved CFeeRate into ./policy/. This does not appear to be the case with Goldcoin.

Reference: https://github.com/dogecoin/dogecoin/pull/2497
goldcoin/goldcoin,goldcoin/goldcoin,goldcoin/goldcoin,goldcoin/goldcoin,goldcoin/goldcoin,goldcoin/goldcoin