python3Packages.thriftpy2: apply upstream patch to remove toml dep

- PR https://github.com/NixOS/nixpkgs/pull/431074 updated this package
  from 0.5.2 -> 0.5.3.

- Between 0.5.2 and 0.5.3 a dependency for `toml` was added (see
https://github.com/Thriftpy/thriftpy2/commit/8e226b12750829ee48abc1f883ea0fcf0b13f717).

- The derivation does not include `toml`, so the build failed.

- However, upstream have since removed `toml` in
https://github.com/Thriftpy/thriftpy2/commit/0127d259eb4b96acb060cd158ca709f0597b148c.

- A new upstream version has not been made yet, so apply the patch
  directly to fix the build. When upstream bumps, the patch can be
  removed.

pkgs/development/python-modules/thriftpy2/default.nix

@@ -3,6 +3,7 @@
   buildPythonPackage,
   cython,
   fetchFromGitHub,
+  fetchpatch,
   ply,
   pythonOlder,
   six,
@@ -24,6 +25,12 @@ buildPythonPackage rec {
     hash = "sha256-idUKqpyRj8lq9Aq6vEEeYEawzRPOdNsySnkgfhwPtMc=";
   };
 
+  patches = [
+    (fetchpatch {
+      url = "https://github.com/Thriftpy/thriftpy2/commit/0127d259eb4b96acb060cd158ca709f0597b148c.patch";
+      sha256 = "sha256-UBcbd8NTkPyko1s9jTjKlQ7HprwtyOZS0m66u1CPH3A=";
+    })
+  ];
   build-system = [ setuptools ];
 
   nativeBuildInputs = [ cython ];