[issue20649] Minor grammatical mistake for asyncio dev docs

[Roundup Robot]

Roundup Robot added the comment:

New changeset 38516b2ffe92 by Victor Stinner in branch '3.4':
Close #20649: Fix typo in asyncio doc. Patch written by Brett Cannon.
http://hg.python.org/cpython/rev/38516b2ffe92

----------
stage: needs patch -> committed/rejected

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue20649>
_______________________________________