dns/dnscrypt-proxy: Replace 'cisco' (OpenDNS) resolver by 'random'

This update replaces the default resolver used by
dnscrypt-proxy (cisco/OpenDNS) by a random one that
does not log entries and supports dnssec.

• Improve pkg-message's.
• Fix MASTER_SITES.
• Reorder Makefile variable's.
• Update WWW.

PR: 223222
Submitted by: Vinícius Zavam <egypcio@googlemail.com>
Reviewed by: dbaio, garga, mat
Approved by: Leo Vandewoestijne <freebsd@dns-lab.com>

		(maintainer, previous patch, then timeout)

Differential Revision: https://reviews.freebsd.org/D12775