can't install with go

```
$ go get -u github.com/OpenBazaar/multiwallet
go get: github.com/ltcsuite/ltcutil@none updating to
        github.com/ltcsuite/ltcutil@v1.0.2: parsing go.mod:
        module declares its path as: github.com/btcsuite/btcutil
                but was required as: github.com/ltcsuite/ltcutil
```