Bug#511452: one more problem with d-i reusing RAID partitions

[Michael Goetze <mgoetze@mgoetze.net>]

> It seems it kept believing in (parts of) QNAP's original RAID
> configuration.

This was also sort of the "feeling" I got, but actually after I 
deactivated the swap partitions I was able to delete md0 and create a 
fresh one without problems.