[docs] [issue28978] a redundant right parentheses in the EBNF rules of parameter_list

[woo yoo]

woo yoo added the comment:

Code:
>>>def f(a, *):
>>>    print(a)
....
....（SyntaxError occurs here）

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue28978>
_______________________________________