'django.contrib.messages.context_processors.messages' must be enabled in DjangoTemplates

[pgajdos]

During creating test database I get:

SystemCheckError: System check identified some issues:
 
ERRORS:
 ?: (admin.E404) 'django.contrib.messages.context_processors.messages' must be enabled in DjangoTemplates (TEMPLATES) in order to use the admin application.
 
System check identified 1 issue (0 silenced).

Doing what the error message suggests fixes the issue for me. Hence I am not familiar with the code sufficiently in my opinion, I do not dare to make a PR. I can do on demand, though.

[pgajdos]

System info: python 3.7 on linux x86_64

[pgajdos]

Thanks!