gh-XXXXX: Fix optparse._check_callback TypeError for tuple callback_kwargs

%r % tuple unpacks the tuple as multiple format args, raising TypeError
instead of OptionError. Wrap in a 1-tuple: % (value,).

Author: stefanzetzsche

Lib/optparse.py

@@ -704,7 +704,7 @@ def _check_callback(self):
                 not isinstance(self.callback_kwargs, dict)):
                 raise OptionError(
                     "callback_kwargs, if supplied, must be a dict: not %r"
-                    % self.callback_kwargs, self)
+                    % (self.callback_kwargs,), self)
         else:
             if self.callback is not None:
                 raise OptionError(