Disable anonymous postings by returning a 404.
Disable anonymous postings by returning a 404.

See #852.

manhhomienbienthuy/pythondotorg,python/pythondotorg,proevo/pythondotorg,manhhomienbienthuy/pythondotorg,python/pythondotorg,proevo/pythondotorg,malemburg/pythondotorg,python/pythondotorg,manhhomienbienthuy/pythondotorg,Mariatta/pythondotorg,proevo/pythondotorg,malemburg/pythondotorg,proevo/pythondotorg,Mariatta/pythondotorg,Mariatta/pythondotorg,malemburg/pythondotorg,manhhomienbienthuy/pythondotorg,python/pythondotorg,malemburg/pythondotorg,Mariatta/pythondotorg