traceroute: uprev it to 2.0.20

1. uprev to 2.0.20
2. Update the license md5sum, since the address is changed in COPYING*:
From:
    Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
To:
    Copyright (C) 1989, 1991 Free Software Foundation, Inc.
    59 Temple Place, Suite 330, Boston, MA  02111-1307

Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>