Motivation for this change

Debian changed git servers for pkg-multimedia, and the patches are no longer available:

$ curl -Lv https://anonscm.debian.org/cgit/pkg-multimedia/audiofile.git/plain/debian/patches/04_clamp-index-values-to-fix-index-overflow-in-IMA.cpp.patch?h=debian/0.3.6-4

< HTTP/1.1 404 Not found
< Date: Fri, 02 Feb 2018 18:13:41 GMT
< Server: Apache/2.2.22 (Debian)
< Expires: Thu, 01 Jan 1970 00:00:05 GMT
< Last-Modified: Fri, 02 Feb 2018 18:13:41 GMT
< X-Robots-Tag: noindex, nofollow
< Vary: Accept-Encoding
< Transfer-Encoding: chunked
< Content-Type: text/html; charset=UTF-8

This is causing my builds to fail, the issue has not been detected in nixpkgs/trunk due to caching.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option build-use-sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Fits CONTRIBUTING.md.