diagnose: Fix reversed logic when fixing PATH
diagnose: Fix reversed logic when fixing PATH

Although counterintuitively, the ui_options(questions_yesno) proc will
return 0 for yes and 1 for no.

macports/macports-base,neverpanic/macports-base,macports/macports-base,danchr/macports-base,danchr/macports-base,neverpanic/macports-base