Stick-Update with SSD#462

• After upgrading to an SSD:
Boot from the (OS) backup USB drive and run the update;
the update is performed on the SSD rather than on the drive itself.
(Not tested with the original drive (instead of ssd) versus the backup drive; tested only via SSD.)

• Temporary solution:
Temporarily disable the SATA controller in the BIOS, boot, perform the update, then re-enable the SATA controller.

• Fix:
The update function must update the current boot drive.