Fix: swap event feeAmount argument is using the wrong value

[Alexander]

See

portfolio/contracts/Portfolio.sol

Line 522 in a2a43a9

 iteration.feeAmount = iteration.input.scaleFromWadDown(inputDec); 

Incorrectly setting feeAmount, which gets emitted in the Swap event, to the a double scaled down iteration.input value. This line needs to be updated to feeAmount.

[Clément Lakhal]

Closing this as it's now fixed.