Pull request 1798: 4262-ipv6-pref

Updates #4262.

Squashed commit of the following:

commit de64f9c40c00317dbb5dbdda900d9b4c574a0a32
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Mon Apr 3 19:23:15 2023 +0300

    all: add ipv6 boostrap pref

internal/home/clients.go

@@ -408,6 +408,7 @@ func (clients *clientsContainer) findUpstreams(
 			Bootstrap:    config.DNS.BootstrapDNS,
 			Timeout:      config.DNS.UpstreamTimeout.Duration,
 			HTTPVersions: dnsforward.UpstreamHTTPVersions(config.DNS.UseHTTP3Upstreams),
+			PreferIPv6:   config.DNS.BootstrapPreferIPv6,
 		},
 	)
 	if err != nil {