Update Lib/configparser.py

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

Author: lpyu001

Lib/configparser.py

@@ -1222,8 +1222,6 @@ def _unify_values(self, section, vars):
     def _convert_to_boolean(self, value):
         """Return a boolean value translating from other types if necessary.
         """
-        if value is None:
-            raise ValueError('Not a boolean: None')
         if value is None or value.lower() not in self.BOOLEAN_STATES:
             raise ValueError('Not a boolean: %s' % value)
         return self.BOOLEAN_STATES[value.lower()]