tnef: remove duplicate file

pkgs/applications/misc/tnef/tnef/default.nix

@@ -1,30 +0,0 @@
-{ fetchurl, lib }:
-
-stdenv.mkDerivation rec {
-  version = "1.4.12";
-  name = "tnef-${version}";
-
-  src = fetchFromGitHub {
-    owner = "verdammelt";
-    repo = "tnef";
-    rev = "${version}";
-    sha256 = "0ssi2wpaf7plaswqqjwigppsg5fyh99vdlb9kzl7c9lng89ndq1i";
-  };
-
-  doCheck = true;
-
-  meta = with lib; {
-    description = "Unpacks MIME attachments of type application/ms-tnef";
-    longDescription = ''
-      TNEF is a program for unpacking MIME attachments of type "application/ms-tnef". This is a Microsoft only attachment.
-
-      Due to the proliferation of Microsoft Outlook and Exchange mail servers, more and more mail is encapsulated into this format.
-
-      The TNEF program allows one to unpack the attachments which were encapsulated into the TNEF attachment. Thus alleviating the need to use Microsoft Outlook to view the attachment.
-    '';
-    homepage = https://github.com/verdammelt/tnef;
-    license = licenses.gpl2;
-    maintainers = [ maintainers.DamienCassou ];
-    platforms = platforms.all;
-  };
-}