iotests: Respect -nodefaults in tests 41 and 55 While -nodefaults is set in $QEMU_OPTIONS, this is currently (wrongly) ignored for Python iotests. In order to be prepared for when this is fixed, we should explicitly add an IDE CD-ROM drive instead of relying on it being created automatically. Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>