Review build error on `demo-wallet-sdk-react`

[arboleya]

Getting this when trying to pnpm build on master, using a fresh clone:

[petertonysmith94]

Related issue with the connectors: https://github.com/FuelLabs/fuel-connectors/issues/52

[mvares]

That is likely because the code is being executed on the server-side. (PS: Due to this, the window variable isn't available)

Perhaps we can get a look at Fuel Connector code and send a PR to fix this bug.