Used the override version of nix and not the default one provided by nixpkgs.
Used the override version of nix and not the default one provided by nixpkgs.

git-svn-id: a8013ee9bf6b053da8ea218c5059f3906c3a3af2@14989 70bd8c7a-acb8-0310-9f0d-9cc1c95dcdbb

bnordgren/nixos,bnordgren/nixos,bnordgren/nixos,bnordgren/nixos,bnordgren/nixos