Issue Fix icons in "Migration results" pane during re-sync

[nineproof]

While re-syncing a migration succeeded (green mark) or a migration succeeded with warnings (yellow mark), the "Migration results" pane shows the error mark (red) if there are failed migration attempts before the succeeded one.

The icon should reflect the status of the last attempt or show a spinner.

Please see the screenshot attached: on the left pane you can see migration of "intexo.it" is in progress; on the right you can see the Migration results shows an error mark for intexo.it. Please note that last migration attempt ended with warnings (not errors), so the yellow mark was correctly displayed until starting re-syncing.