bug#33000: openal 404 "Not Found"

[Nam Nguyen]

When trying to build OpenAL, I get a 404 "Not Found."

> download failed 
> "http://tarballs.nixos.org/sha256/1mhf5bsb58s1xk6hvxl7ly7rd4rpl9z8h07xl1q94brywykg7bgi";
>  404 "Not Found"
> failed to download 
> "/gnu/store/3bdqdxl3aribv35dcp2glx8sg3slxxkx-openal-soft-1.19.0.tar.bz2" from 
> "http://kcat.strangesoft.net/openal-releases/openal-soft-1.19.0.tar.bz2";

The project homepage may have moved from
http://kcat.strangesoft.net/openal-releases/ to
http://openal-soft.org/openal-releases/.

I arrived at this from this commit on their Github repository.
https://github.com/kcat/openal-soft/commit/6562a939ea5a5b582d6aa182f3f6fa7411a5e222#diff-04c6e90faac2675aa89e2176d2eec7d8

I am not sure if the original website is just temporarily down or if
it has moved. The Github repository mentions the official website being
openal-soft.org. Sources are also available on Github but with a different
extension.

Something like this worked when I tested it:
$ diff -u audio.scm audio.scm.2
--- audio.scm   2018-10-09 22:23:12.750628879 -0700
+++ audio.scm.2 2018-10-09 22:23:58.158478413 -0700
@@ -1913,7 +1913,7 @@
     (source (origin
               (method url-fetch)
               (uri (string-append
-                    "http://kcat.strangesoft.net/openal-releases/openal-soft-";
+                    "http://openal-soft.org/openal-releases/openal-soft-";
                     version ".tar.bz2"))
               (sha256
                (base32