odhcpd: Fix a segfault in DHCPv6 option handling

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40881 3c298f89-4303-0410-b956-a3cf2f4a3e73
busybox: remove redundant 6rd-patch

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@40882 3c298f89-4303-0410-b956-a3cf2f4a3e73