Avoid cython due to build error:
	ValueError: 'rencode/rencode.pyx' doesn't match any files

Remove platform specific optimizations.

Index: setup.py
--- setup.py.orig
+++ setup.py
@@ -36,12 +36,12 @@ except ImportError as ex:
     from setuptools.command.build_ext import build_ext
     cythonize = False
 
+cythonize = False
 source_ext = ".pyx" if cythonize else ".c"
 
 ext_modules = [
     Extension(
         "rencode._rencode",
-        extra_compile_args=["-O3"],
         sources=["rencode/rencode" + source_ext],
     ),
 ]