mailman: update from 2.1.17 to 2.1.18

pkgs/servers/mail/mailman/default.nix

···
-{ stdenv, fetchurl, python }:
+{ stdenv, fetchurl, python, dnspython }:
 
 stdenv.mkDerivation rec {
-  name = "mailman-2.1.17";
+  name = "mailman-2.1.18";
 
   src = fetchurl {
     url = "mirror://gnu/mailman/${name}.tgz";
-    sha256 = "1rws4ghpq78ldp1si3z4pmiv1k4l8g6i6hjb2y4cwsjlxssahc64";
+    sha256 = "0jc360crakvpz71msl0h11zv3849fqzlj9jfh1g7x3j4459n07fw";
   };
 
-  buildInputs = [ python ];
+  buildInputs = [ python dnspython ];
 
   patches = [ ./fix-var-prefix.patch ];
 

pkgs/top-level/all-packages.nix

···
 
   lighttpd = callPackage ../servers/http/lighttpd { };
 
-  mailman = callPackage ../servers/mail/mailman { };
+  mailman = callPackage ../servers/mail/mailman {
+    dnspython = pythonPackages.dns;
+  };
 
   mediatomb = callPackage ../servers/mediatomb {
     spidermonkey = spidermonkey_185;