Busybox does not support the 'scope' argument on 'ip address add' or 'ip
route add', this is documented in BUSYBOX.md, but is no longer actually
needed, as the kernel does get it right without manual specification,
and the ifconfig variant already relies on the kernel to get it right.
This is part of #103.
X-Gentoo-Bug: 487208
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=487208