Truncation bugfixes for downloading.
Truncation bugfixes for downloading.

When _get_original_media decides to actually download
the original media (as opposed to using the cached
version), it needs to truncate the file to make sure there
is no stale data still lying around.

Signed-off-by: Chris Lalancette <60b62644009db6b194cc0445b64e9b27bb26433a@redhat.com>

clalancette/oz,ndonegan/oz,mgagne/oz,moofrank/oz,nullr0ute/oz,cernops/oz,NeilBryant/oz,cernops/oz,NeilBryant/oz,clalancette/oz,moofrank/oz,mgagne/oz,imcleod/oz,imcleod/oz,nullr0ute/oz,ndonegan/oz