Fix 500 error as request.user is None at this stage

When trying to log out on Google App Engine I receive a ```500``` because request.user at this stage is None. Removing the next line solves the problem and we are able to logout without issues. As ```django_user``` is the current user I am not sure what you are trying to achieve with this, but it doesn't work. 

```
Internal Server Error: /
Traceback (most recent call last):
  File "/base/data/home/apps/s~aevitas-rpg/1.380750887726969414/sitepackages/django/core/handlers/base.py", line 88, in get_response
    response = middleware_method(request)
  File "/base/data/home/apps/s~aevitas-rpg/1.380750887726969414/sitepackages/djangae/contrib/gauth/middleware.py", line 22, in process_request
    django_user = request.user
AttributeError: 'WSGIRequest' object has no attribute 'user'
```