bug#64401: 28.1; Desktop restoration

[Tom Hunt]

> 
> 
> desktop.el already tries to do that, see desktop-files-not-to-save.
> Any idea why it doesn't work in your case?

I've set desktop-files-not-to-save to nil. This is because I explicitly want 
remote files saved, most of the time. (Much of my emacs workflow involves 
remote files; if they aren't saved then desktop saving is substantially less 
useful.)

The problem isn't at save time, it's at restore time. The issue is that, if a 
saved remote file isn't reachable, it hangs the whole restore. Ideally, an 
unreachable saved file would just be skipped over (at restore time) and the 
rest of the session restored.