[Tails-dev] Adding another SanDisk to the problematic USBs l…

Hi,

According to a user report I added another problematic SanDisk to the
list in the known issues page, to review and merge from:

mercedes508 known_issues/SanDisk 0d34ce32949

But I was wondering if it's relevant to add the different size of each
affected model, as here I'm just adding the SanDisk Ultra 16GB, but the
SanDisk Ultra 32GB was already in the list.

I don't remeber any problematic SanDisk to be working for a given size
and ot another.

Thoughts?

Cheers.