[docs] [issue22603] Fix a typo in the contextlib docs

Roundup Robot added the comment: New changeset 50bedeffec2f by Terry Jan Reedy in branch '3.4': Issue 22603: add Francisco Fernández Castaño to ACKS. https://hg.python.org/cpython/rev/50bedeffec2f ---------- _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue22603> _______________________________________