E.g. <http://apache.belnet.be/jakarta/oro/jakarta-oro-2.0.8.tar.gz>
redirects to a bogus 200 HTML page.
* guix/download.scm (%mirrors): Replace apache.belnet.be with
ftp.nluug.nl.
(apache ; from http://www.apache.org/mirrors/dist.html
"http://www.eu.apache.org/dist/"
"http://www.us.apache.org/dist/"
- "http://apache.belnet.be/"
+ "https://ftp.nluug.nl/internet/apache/"
"http://apache.mirror.iweb.ca/"
"http://mirrors.ircam.fr/pub/apache/"
"http://apache.mirrors.ovh.net/ftp.apache.org/dist/"