Security fix, CVE-2017-14491 DNS heap buffer  overflow.
    
    Fix heap overflow in DNS code. This is a potentially serious
    security hole. It allows an attacker who can make DNS
    requests to dnsmasq, and who controls the contents of
    a domain, which is thereby queried, to overflow
    (by 2 bytes) a heap buffer and either crash, or
    even take control of, dnsmasq.
    
    Signed-off-by: Petr Menšík <pemensik@redhat.com>