Allow the application to start without Monero connection
Currently if the user sets a custom node in the UI, and the custom node is not available during startup, then the application will not be able to start.

Bisq has the same issue: https://bisq.wiki/Connecting_to_your_own_Bitcoin_node#troubleshooting

The current solution is to start the application with `--xmrNode` or `--xmrNodes` startup flags so the application can connect and start.

This issue requests a way to recover from this state without startup flags.

Ideally the user can start the application in a disconnected state, adjust the network settings, and then restart.