luci-app-ddns: fix huge typo in luasrc/tools/ddns.lua
luci-app-ddns: fix huge typo in luasrc/tools/ddns.lua

Signed-off-by: David Yang <90daeb2ad8a5fefd3510aa6b5f6d719f6a4cd9ae@gmail.com>

Noltari/luci,hnyman/luci,lbthomsen/openwrt-luci,Noltari/luci,rogerpueyo/luci,hnyman/luci,lbthomsen/openwrt-luci,openwrt/luci,artynet/luci,lbthomsen/openwrt-luci,hnyman/luci,tobiaswaldvogel/luci,nmav/luci,Noltari/luci,nmav/luci,artynet/luci,artynet/luci,openwrt/luci,openwrt-es/openwrt-luci,artynet/luci,artynet/luci,hnyman/luci,openwrt/luci,rogerpueyo/luci,openwrt-es/openwrt-luci,artynet/luci,hnyman/luci,tobiaswaldvogel/luci,openwrt/luci,artynet/luci,rogerpueyo/luci,nmav/luci,openwrt-es/openwrt-luci,openwrt/luci,openwrt-es/openwrt-luci,Noltari/luci,artynet/luci,Noltari/luci,Noltari/luci,tobiaswaldvogel/luci,tobiaswaldvogel/luci,rogerpueyo/luci,nmav/luci,nmav/luci,openwrt-es/openwrt-luci,openwrt-es/openwrt-luci,lbthomsen/openwrt-luci,nmav/luci,Noltari/luci,openwrt-es/openwrt-luci,hnyman/luci,openwrt-es/openwrt-luci,openwrt/luci,rogerpueyo/luci,openwrt/luci,nmav/luci,rogerpueyo/luci,Noltari/luci,hnyman/luci,lbthomsen/openwrt-luci,artynet/luci,tobiaswaldvogel/luci,lbthomsen/openwrt-luci,openwrt/luci,Noltari/luci,rogerpueyo/luci,tobiaswaldvogel/luci,hnyman/luci,tobiaswaldvogel/luci,nmav/luci,lbthomsen/openwrt-luci,lbthomsen/openwrt-luci,rogerpueyo/luci,nmav/luci,tobiaswaldvogel/luci