python.pkgs.errbot-rocket: add patch to fix IPv6

pkgs/development/python-modules/rocket-errbot/default.nix

···
+{ lib, fetchurl, fetchpatch, buildPythonPackage }:
+
+buildPythonPackage rec {
+  name = "rocket-errbot-${version}";
+  version = "1.2.5";
+
+  src = fetchurl {
+    url = "mirror://pypi/r/rocket-errbot/${name}.tar.gz";
+    sha256 = "181y1wqjvlry5xdzbliajvrxvswzh3myh795jnj1pm92r5grqzda";
+  };
+
+  # remove with 1.2.6
+  patches = [ (fetchpatch {
+    url = "https://github.com/errbotio/rocket/pull/1.patch";
+    sha256 = "0v9zjp4ls32vkpr4b6kjflz4ny2fwj6hwshbnjmhdzc4hnmnzf7x";
+  }) ];
+
+  meta = {
+    homepage = https://github.com/errbotio/rocket;
+    description = "Modern, multi-threaded and extensible web server";
+    license = lib.licenses.mit;
+  };
+}
+

pkgs/top-level/python-packages.nix

···
     };
   };
 
-  rocket-errbot = buildPythonPackage rec {
-    name = "rocket-errbot-${version}";
-    version = "1.2.5";
-
-    src = pkgs.fetchurl {
-      url = "mirror://pypi/r/rocket-errbot/${name}.tar.gz";
-      sha256 = "181y1wqjvlry5xdzbliajvrxvswzh3myh795jnj1pm92r5grqzda";
-    };
-  };
+  rocket-errbot = callPackage ../development/python-modules/rocket-errbot {  };
 
   Yapsy = buildPythonPackage rec {
     name = "Yapsy-${version}";