[BUG] "Lightning not running" when paying quickly

[SeverinAlexB]

How to reproduce:

1. Starting Bitkit from scratch
2. Quickly pay and invoice.
3. Error -> Lightning not running

I guess LDK takes a moment to start.

IMG_5681.MP4

[ben-kaufman]

Need to add an initializing screen like in Android

[pwltr]

This also needs some fixing to be able to handle deep links. See related Android issue: synonymdev/bitkit-android#623

[piotr-iohk]

Not critical as per @JeanlChristophe. Removing mustfix.