Getting 401 error: unauthorized when using createWalletWasm() with local node
**versions**:
monero-javascript 0.4.3
monerod v0.16.0.3
node v14.9.0
npm 6.14.8
react 16.13.1
babel core 7.11.4
webpack 4.44.1
webpack-dev-server 3.11.0

**usage**:
`./monerod --stagenet --rpc-login superuser:abctesting123 --rpc-access-control-origins http://localhost:8080`

then I start the webpack-dev-server on http://localhost:8080

**relevant code**:
```
const monerojs = require("monero-javascript");

let walletRpc = new monerojs.MoneroRpcConnection({
  //uri: "http://stagenet.community.xmr.to:38081",
  uri: "http://localhost:38081",
  username: "superuser",
  password: "abctesting123",
  rejectUnauthorized: false, // e.g. local development
});

export async function createWallet(lang = "English") {
  console.log("Creating new wallet");
  let walletWasm = await monerojs.createWalletWasm({
    networkType: "stagenet",
    language: lang,
    password: "pass123",
    server: walletRpc,
  });
  return walletWasm;
}
```

**error**:
on host system macOS 10.15.6
for both Firefox 80.0.1 and Brave 1.13.82 (Chromium 85.0.4183.83)
in the browser console:
```
XHRPOSThttp://localhost:38081/json_rpc
[HTTP/1.1 401 Unauthorized 0ms]
```


If I try to use the JSON RPC with Postman I get it to work, but not with monero-javascript and the WASM Wallet in the browser. Am I doing something wrong?

Thanks!