fix typo in configparser doc (GH-12154)

Lib/configparser.py

@@ -56,7 +56,7 @@ ConfigParser -- responsible for parsing a list of
 
         When `interpolation` is given, it should be an Interpolation subclass
         instance. It will be used as the handler for option value
-        pre-processing when using getters. RawConfigParser object s don't do
+        pre-processing when using getters. RawConfigParser objects don't do
         any sort of interpolation, whereas ConfigParser uses an instance of
         BasicInterpolation. The library also provides a ``zc.buildbot``
         inspired ExtendedInterpolation implementation.