Don't delete all cookies whose names start with "ckan"

I'm writing a CKAN extension and I had to set my own cookie (I couldn't use the beaker session, because I need my cookie to be set and persist when the user is not logged in. and CKAN or Pylons seems to clear the session on each page load when you're not logged in). I created my cookie and called it "ckanext-oauth2waad-state". The cookie is correctly set and stored in my browser, but for some reason the browser does not send the cookie back to CKAN on subsequent page requests.

Half a day later, I found that in its response to the `/en` URL which is requested as part of every page load, CKAN finds all cookies whose names start with "ckan" and deletes them.