Fixes
In file included from init.cpp:46:
./wallet/wallet.h:80:1: warning: class 'FeeCalculation' was previously declared as a struct [-Wmismatched-tags]
class FeeCalculation;
^
./policy/fees.h:113:8: note: previous use is here
struct FeeCalculation
^
./wallet/wallet.h:80:1: note: did you mean struct here?
class FeeCalculation;
^~~~~
struct
1 warning generated.