README: bzip2 is not new

From: Hkon Lvdal <Hakon.Lovdal@ericsson.com>

Signed-off-by: Hkon Lvdal <Hakon.Lovdal@ericsson.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>