Fix test failures in Python 3.8 (fixes #6594)
Fix test failures in Python 3.8 (fixes #6594)

I am not sure whether this is the correct fix but the test suite passes.
akshayaurora/kivy,inclement/kivy,matham/kivy,akshayaurora/kivy,matham/kivy,matham/kivy,rnixx/kivy,rnixx/kivy,rnixx/kivy,matham/kivy,inclement/kivy,inclement/kivy,kivy/kivy,akshayaurora/kivy,kivy/kivy,kivy/kivy