The site is no longer working
$ grep MAINTAINER Mk/bsd.sites.mk # Sites_MAINTAINER= ports@FreeBSD.org
A commit references this bug: Author: pi Date: Wed Aug 9 16:39:57 UTC 2017 New revision: 447633 URL: https://svnweb.freebsd.org/changeset/ports/447633 Log: Mk/bsd.sites.mk: remove mysql.mirrored.ca from MASTER_SITE_MYSQL - The site is redirected to a click-farm PR: 221364 Changes: head/Mk/bsd.sites.mk
Thanks for the pointer to the MAINTAINER field 8-)