Revert r63323: Use lowercase version of module name.

The distutils module should continue to use the old ConfigParser name,
for backward-compatibility.
diff --git a/Lib/distutils/config.py b/Lib/distutils/config.py
index edba47f..f1117be 100644
--- a/Lib/distutils/config.py
+++ b/Lib/distutils/config.py
@@ -5,7 +5,7 @@
 """
 import os
 import sys
-from configparser import ConfigParser
+from ConfigParser import ConfigParser
 
 from distutils.cmd import Command