Use a opção WSGIRestrictStdout:
WSGIRestrictStdout Off
ou substitua sys.stdout por sys.stderr no script estrela do Django WSGI:
import sys
sys.stdout = sys.stderr
No WSGI application component which claims to be portable should write to standard output. That is, an application should not use the Python print statement without directing output to some alternate stream. An application should also not write directly to sys.stdout.