which 2.18: fix SRC_URI

It is the GPLv2+ version, the old SRC_URI is down, use fedoraproject's
repo. Its homepage is also down, but I can't find a new one for it.

(From OE-Core rev: 41c4bad1)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>