Python: replace mkPythonDerivation with buildPythonPackage and format="other";

This way all Python packages use the same function,
`buildPythonPackage`.

pkgs/development/python-modules/koji/default.nix

@@ -1,7 +1,8 @@
-{ stdenv, fetchurl, mkPythonDerivation, pycurl }:
+{ stdenv, fetchurl, buildPythonPackage, pycurl }:
 
-mkPythonDerivation rec {
+buildPythonPackage rec {
   name = "koji-1.8";
+  format = "other";
 
   src = fetchurl {
     url = "https://fedorahosted.org/released/koji/koji-1.8.0.tar.bz2";