Set site before long_slug on generic list view
Used self site in set channel long slug generic view base
Check exist channel long slug on get context data, if not context is empty list
Check exist channel long slug on get template names, if not exist set none template
Add containers none template, if not exist channel long slug
fix pep8, opps/views/generic/base.py:8:1: F401 ImproperlyConfigured imported but unused