[bug] Backup restore: Modal success dialog should not use "Warning" icon

[g80vm...@riseup.net]

When restoring from backup, successful completion results in a modal
dialog labeled, "Finished successfully!". This dialog uses an
exclamation point-style "Warning" icon. This icon gives the user the
wrong impression. Instead, the icon should be a green checkmark or
something similarly recognizable as an indicator of success.

[AJ Jordan]

I would suggest filing a bug in the issue tracker[1], where it is much
more likely to be noticed by the developers. More broadly the Qubes UI
is full of icon problems of this nature; see for example issue
#4922[2] which is *exactly* the same problem as the one you've
noticed.

[1]: https://github.com/QubesOS/qubes-issues/issues
[2]: https://github.com/QubesOS/qubes-issues/issues/4922