mdf2iso: switch to Debian mirror

mdf2iso went away when BerliOS closed, and doesn't appear to have a
new homepage yet.

Fixes Homebrew/legacy-homebrew#30699.

Formula/mdf2iso.rb

@@ -2,8 +2,8 @@
 
 class Mdf2iso < Formula
   homepage 'http://mdf2iso.berlios.de/'
-  url 'http://download.berlios.de/mdf2iso/mdf2iso-0.3.0-src.tar.bz2'
-  sha1 'd424bd84a2c45834d7b7060306aa9ee1926c9215'
+  url 'http://ftp.de.debian.org/debian/pool/main/m/mdf2iso/mdf2iso_0.3.0.orig.tar.gz'
+  sha1 '949d4fa0bb1e40ca17842a265d8ed813bac4917a'
 
   def install
     system "./configure", "--disable-debug", "--disable-dependency-tracking",