Fix race issue with protocol registration

[dedo1911]

app.on('ready') is fired before app.waitReady and allows the protocol to be registered earlier.

Should fix #15 and fix #18

[sindresorhus]

This doesn't answer why it works in development and not in production though.

app.whenReady() should be equivalent to app.on('ready'). Can you open an Electron issue about this?

[sindresorhus]

Thanks for fixing this 🙌

[dedo1911]

In my case it was working in development because the app was being served on a local development server (localhost:3000). That's why it appeared to be release only issue.
However forcing it to use the serve scheme in dev, it stopped working either.

[sindresorhus]

Ah, that makes sense.