pulseaudio-dlna: Fix build by downgrading zeroconf

pkgs/applications/audio/pulseaudio-dlna/default.nix

@@ -14,7 +14,10 @@ assert flacSupport -> flac != null;
 assert soxSupport -> sox != null;
 assert vorbisSupport -> vorbisTools != null;
 
-pythonPackages.buildPythonApplication rec {
+let
+  zeroconf = pythonPackages.callPackage ./zeroconf.nix { };
+
+in pythonPackages.buildPythonApplication rec {
   pname = "pulseaudio-dlna";
   version = "2017-11-01";
 
@@ -30,7 +33,8 @@ pythonPackages.buildPythonApplication rec {
 
   propagatedBuildInputs = with pythonPackages; [
     dbus-python docopt requests setproctitle protobuf psutil futures
-    chardet notify2 netifaces pyroute2 pygobject2 lxml zeroconf ]
+    chardet notify2 netifaces pyroute2 pygobject2 lxml ]
+    ++ [ zeroconf ]
     ++ stdenv.lib.optional mp3Support lame
     ++ stdenv.lib.optional opusSupport opusTools
     ++ stdenv.lib.optional faacSupport faac

pkgs/applications/audio/pulseaudio-dlna/zeroconf.nix

@@ -0,0 +1,31 @@
+{ stdenv
+, buildPythonPackage
+, fetchPypi
+, ifaddr
+, typing
+, isPy27
+, pythonOlder
+, netifaces
+, six
+, enum-compat
+}:
+
+buildPythonPackage rec {
+  pname = "zeroconf";
+  version = "0.19.1";
+
+  src = fetchPypi {
+    inherit pname version;
+    sha256 = "0ykzg730n915qbrq9bn5pn06bv6rb5zawal4sqjyfnjjm66snkj3";
+  };
+
+  propagatedBuildInputs = [ netifaces six enum-compat ifaddr ]
+    ++ stdenv.lib.optionals (pythonOlder "3.5") [ typing ];
+
+  meta = with stdenv.lib; {
+    description = "A pure python implementation of multicast DNS service discovery";
+    homepage = https://github.com/jstasiak/python-zeroconf;
+    license = licenses.lgpl21;
+    maintainers = [ ];
+  };
+}