functional_tests: Failures due to RemovedInPytest4Warning

orequest = <SubRequest 'session_tmpdir' for <Function 'test_browser_waits_for_redirect_after_restoring_a_backup'>>
otmpdir_factory = TempdirFactory(_tmppath_factory=TempPathFactory(_given_basetemp=None, _trace=<pluggy._tracing.TagTracerSub object at 0x7f28a54e7cf8>, _basetemp=None))
o
o    @pytest.fixture(scope='session')
o    def session_tmpdir(request, tmpdir_factory):
o        """pytest tmpdir which is session-scoped."""
o        from _pytest.tmpdir import tmpdir
o>       return tmpdir(request, tmpdir_factory)
oE       _pytest.warning_types.RemovedInPytest4Warning: Fixture "tmpdir" called directly. Fixtures are not meant to be called directly, are created automatically when test functions request them as parameters. See https://docs.pytest.org/en/latest/fixture.html for more information.