[Bug]: Error defining custom network when the wallet is connected

### Bug description

when wallet is connected, if you try to save a new custom network, it will fail with:
```
: Expected an array with at least one valid string HTTPS url 'rpcUrls', Received:
undefined
```

### Expected behavior

it should disconnect the wallet instead of erroring.

Furthermore:
- There could be a textbox to specify a wasp-api, if that is specified, the wallet should be prompted to switch to that new jsonrpc.

### Can the issue reliably be reproduced?

Yes