buildroot

c-ares: security bump to version 1.13.0

Fixes the following security issues:

CVE-2017-1000381: The c-ares function `ares_parse_naptr_reply()`, which is
used for parsing NAPTR responses, could be triggered to read memory outside
of the given input buffer if the passed in DNS response packet was crafted
in a particular way.

https://c-ares.haxx.se/adv_20170620.html

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>