Make the ascii progress bar really be ascii, not Unicode
Make the ascii progress bar really be ascii, not Unicode

Found while debugging #5665

pfmoore/pip,xavfernandez/pip,pypa/pip,xavfernandez/pip,rouge8/pip,pfmoore/pip,sbidoul/pip,xavfernandez/pip,pradyunsg/pip,sbidoul/pip,pradyunsg/pip,rouge8/pip,rouge8/pip,pypa/pip