tests: remove un-used settings fixture with south tests
tests: remove un-used settings fixture with south tests

bforchhammer/pytest-django,ktosiek/pytest-django,tomviner/pytest-django,thedrow/pytest-django,hoh/pytest-django,pelme/pytest-django,ojake/pytest-django,RonnyPfannschmidt/pytest_django,reincubate/pytest-django,aptivate/pytest-django,pombredanne/pytest_django,felixonmars/pytest-django,davidszotten/pytest-django