package/bind: Enable filter-aaaa-on-v4 option

This allows usage of the filter-aaaa-on-v4 configuration option.
This option disables responding with AAAA records when the request
	is made over ipv4. This may be useful on networks with
	ipv6 inside, but no ISP ipv6 (when combined with only
	listening on ipv4).

See https://kb.isc.org/article/AA-00576/


	Filter-AAAA-option-in-BIND-9-.html
	for more information.

Signed-off-by: Nathaniel Roach <nroach44@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>