Remove --debug option from datasette serve

[simonw]

It doesn't appear to do anything useful at all:

datasette/datasette/cli.py

Lines 251 to 253 in f786033

	@click.option(
	"--debug", is_flag=True, help="Enable debug mode - useful for development"
	)

datasette/datasette/cli.py

Lines 365 to 367 in f786033

	kwargs = dict(
	immutables=immutable,
	cache_headers=not debug and not reload,

[simonw]

The only impact it has at all is on this code here:

datasette/datasette/views/base.py

Lines 515 to 527 in cc218fa

	def set_response_headers(self, response, ttl):
	# Set far-future cache expiry
	if self.ds.cache_headers and response.status == 200:
	ttl = int(ttl)
	if ttl == 0:
	ttl_header = "no-cache"
	else:
	ttl_header = "max-age={}".format(ttl)
	response.headers["Cache-Control"] = ttl_header
	response.headers["Referrer-Policy"] = "no-referrer"
	if self.ds.cors:
	response.headers["Access-Control-Allow-Origin"] = "*"
	return response

That ds.cache_headers property looks like it needs rethinking too.