Allow popup prompts within OAuth permission pages

[jackphilippi]

Our slack enterprise channels are secured by our Office 365 OWA auth. This redirects us to a page where we enter our credentials in an authentication prompt. Volt doesn't seem to render this popup prompt so we're not able too utilise the app for work channels.

[voltapp2]

Thanks for reporting this. This is going to be a bit tricky, especially on Windows.

But it's definitely fixable. Will be done this month.