algorithms/symmetry: This is not normal

[Anthchirp]

The function _normalisation is never called.
Flake8 highlighted this since the local variable normalisation is undefined.

I assume this is an oversight that happened during refactoring?

dials/algorithms/symmetry/__init__.py

Lines 135 to 158 in 131a5dc

	def _normalise(self):
	if normalisation is None:
	return
	elif normalisation == "kernel":
	normalise = self.kernel_normalisation
	elif normalisation == "quasi":
	normalise = self.quasi_normalisation
	elif normalisation == "ml_iso":
	normalise = self.ml_iso_normalisation
	elif normalisation == "ml_aniso":
	normalise = self.ml_aniso_normalisation
	for i in range(int(flex.max(self.dataset_ids) + 1)):
	logger.info("Normalising intensities for dataset %i" % (i + 1))
	intensities = self.intensities.select(self.dataset_ids == i)
	if i == 0:
	normalised_intensities = normalise(intensities)
	else:
	normalised_intensities = normalised_intensities.concatenate(
	normalise(intensities)
	)
	self.intensities = normalised_intensities.set_info(
	self.intensities.info()
	).set_observation_type_xray_intensity()