Partially revert "Fix running of setup.py test with recent setuptools. (#84)"

This partially reverts commit be920ea.

Fixes #320

Author: fantix

setup.py

@@ -117,25 +117,13 @@ class uvloop_build_ext(build_ext):
     ]
 
     def initialize_options(self):
-        # initialize_options() may be called multiple times on the
-        # same command object, so make sure not to override previously
-        # set options.
-        if getattr(self, '_initialized', False):
-            return
-
         super().initialize_options()
         self.use_system_libuv = False
         self.cython_always = False
         self.cython_annotate = None
         self.cython_directives = None
 
     def finalize_options(self):
-        # finalize_options() may be called multiple times on the
-        # same command object, so make sure not to override previously
-        # set options.
-        if getattr(self, '_initialized', False):
-            return
-
         need_cythonize = self.cython_always
         cfiles = {}
 
@@ -195,8 +183,6 @@ def finalize_options(self):
 
         super().finalize_options()
 
-        self._initialized = True
-
     def build_libuv(self):
         env = _libuv_build_env()