Remove special handling of 'no_compile' option with comment about making...

Remove special handling of 'no_compile' option with comment about making DISTUTILS_DEBUG work right. While testing on Python 2.6 and later, I was unable to evoke any abberant or distinct behavior by removing the value (with DISTUTILS_DEBUG enabled and using variations of --compile and --no-compile). Therefore, I believe that whatever was the motivation for adding the attribute (in 2c91c12dc9b1), its purpose has passed.

setuptools/command/install.py

@@ -25,7 +25,6 @@ class install(_install):
         _install.initialize_options(self)
         self.old_and_unmanageable = None
         self.single_version_externally_managed = None
-        self.no_compile = None  # make DISTUTILS_DEBUG work right!
 
     def finalize_options(self):
         _install.finalize_options(self)