Fix typo in docstring
Fix typo in docstring

Co-Authored-By: Christopher Hunt <d9a07532a38ba527a979ed6c69435aa25ed87c33@gmail.com>
xavfernandez/pip,pfmoore/pip,pradyunsg/pip,pfmoore/pip,sbidoul/pip,pradyunsg/pip,pypa/pip,sbidoul/pip,pypa/pip,xavfernandez/pip,xavfernandez/pip