[media] get_dvb_firmware: Fix the location of firmware for Terratec HTC

Fix firmware download for the Terratec Cinergy HTC Stick HD. The file
was moved on the server.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>