package/dnsmasq: security bump to 2.83

package/dnsmasq: security bump to 2.83

From the annoucement:
http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2021q1/014599.html

"There are broadly two sets of problems. The first is subtle errors in
dnsmasq's protections against the chronic weakness of the DNS protocol
to cache-poisoning attacks; the Birthday attack, Kaminsky, etc. [...]

[...] the second set of errors is a good old fashioned buffer overflow
in dnsmasq's DNSSEC code."

Fixes CVE-2020-25681, CVE-2020-25682, CVE-2020-25683, CVE-2020-25684,
      CVE-2020-25685, CVE-2020-25686 and CVE-2020-25687

Details: https://www.jsof-tech.com/disclosures/dnspooq

Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>