bareos: Mark as broken

Doesn't have a maintainer.
Doesn't work with our new glusterfs version.
bareos18 has changed from autotools to cmake so the derivation has to be
completely rewritten.

pkgs/tools/backup/bareos/default.nix

@@ -77,5 +77,6 @@ stdenv.mkDerivation rec {
     description = "A fork of the bacula project";
     license = licenses.agpl3;
     platforms = platforms.unix;
+    broken = true;
   };
 }