Fix missing confirm button in Sugar Backup restore

Restore of a Sugar journal backup provided an Accept radio button but
the Confirm button was missing.

This was caused by not calling the show method on the button.

Reported-by: Niraj Nakrani <niraj@laptop.org.au>
Signed-off-by: James Cameron <quozl@laptop.org>
Fix extra blanks in Sugar Backup restore

The restore warning had an extra blank at the start, and an extra blank
before "my journal."

May impact translations.

Signed-off-by: James Cameron <quozl@laptop.org>