Range is not applied to default colormap

[henhuy]

Default colormap (if not setting up a legend) is not working properly (no range attribute set).
This leads to color artefacts like this:

This is related to code in

django-raster/raster/views.py

Lines 82 to 100 in 34fffe3

	if not colormap:
	# Use a continous grayscale color scheme.
	colormap = {
	'continuous': True,
	'from': (0, 0, 0),
	'to': (255, 255, 255),
	}
	else:
	# Add layer level value range to continuous colormaps if it was
	# not provided manually.
	if 'continuous' in colormap and 'range' not in colormap:
	meta = RasterLayerBandMetadata.objects.filter(rasterlayer_id=self.kwargs.get('layer')).first()
	if meta:
	colormap['range'] = (meta.min, meta.max)
	# Filter by custom entries if requested
	if colormap and 'entries' in self.request.GET:
	entries = self.request.GET['entries'].split(',')
	colormap = {k: v for (k, v) in colormap.items() if str(k) in entries}

as range and entries are only added if colormap exists in the first place.
After removing else and unindending range and entries part, raster layer looks as expected: