changed eth wallet adress to fiat

Update LiisaPortfolioTracker payment method.md

We are making the changes to the deliverables for milestone 2 as we encountered some wallets which we do not have documentation for as they are either for mobile (Parity signer) only or there is already a plugin for it in the case of Polkadot.js - https://bubble.io/plugin/polkadot-wallet-1639402639641x977692461648052200 .