'compress_image does not fail when no compression software.'

@mock.patch.object(settings._wrapped, 'OPTIPNG_PATH', None)
@mock.patch.object(kitsune.upload.tasks.subprocess, 'call')
def test_compress_no_compression_software(self, call):

    image = self._uploaded_image()
    compress_image(image, 'file')
    assert (not call.called)
