python2Packages.filelock: use correct version

instead of 0.0.0 when setuptools-scm is not used. This broke virtualenv.

pkgs/development/python-modules/filelock/3.2.nix

@@ -1,4 +1,4 @@
-{ lib, buildPythonPackage, fetchPypi }:
+{ lib, buildPythonPackage, fetchPypi, setuptools-scm }:
 
 buildPythonPackage rec {
   pname = "filelock";
@@ -9,6 +9,10 @@ buildPythonPackage rec {
     sha256 = "1qry67zv2pmz8px6wdfbjqv75nmryy2ac7asqgs6q6db2722kpcw";
   };
 
+  nativeBuildInputs = [
+    setuptools-scm
+  ];
+
   meta = with lib; {
     homepage = "https://github.com/benediktschmitt/py-filelock";
     description = "A platform independent file lock for Python";