lookup IPv4 address only when IPv6 address has changed

homeserverdns-daemon

@@ -157,10 +157,10 @@ function main {
     ip -6 -o monitor address dev $(get_interface) |
     while IFS= read -r line
     do
-        ip4=$(lookup_ip4 "$(declare -p config)")
         local new_ip6=$(parse_ip_monitor_output "${line}")
         #echo "ip-monitor output was ${line}"
         if [ -n "${new_ip6}" ] && [ "${new_ip6}" != "${ip6}" ]; then
+            ip4=$(lookup_ip4 "$(declare -p config)")
             ip6=$new_ip6
             update "${ip4}" "${ip6}" "$(declare -p config)"
         fi