[docs] [issue27618] docs for threading.Lock claim it's a class (since 3.3), but it's not (and has never been, apparently)

[Mariatta Wijaya]

Changes by Mariatta Wijaya <mariatta.wijaya at gmail.com>:


----------
stage:  -> patch review
versions: +Python 2.7, Python 3.7 -Python 3.3, Python 3.4

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue27618>
_______________________________________