c-ares - security update

Gzob Qq discovered that the query-building functions in c-ares, an
asynchronous DNS request library would not correctly process crafted
query names, resulting in a heap buffer overflow and potentially
leading to arbitrary code execution.

For the stable distribution (jessie), this problem has been fixed in
version 1.10.0-2+deb8u1.

For the unstable distribution (sid), this problem has been fixed in
version 1.12.0-1.

We recommend that you upgrade your c-ares packages.