netifd: update to latest version

fixes DNS servers on reload (#12910)
fixes ubus object race on reload or down/up (#12612)

Backport of r35383

git-svn-id: svn://svn.openwrt.org/openwrt/branches/attitude_adjustment@35384 3c298f89-4303-0410-b956-a3cf2f4a3e73