Add SECURE_PROXY_SSL_HEADER setting

Should fix SECURE_SSL_REDIRECT causing infinite loops

Author: paulapreuss

app/epa/settings.py

@@ -269,6 +269,8 @@
 
 if PROD_ENV:
     # SECURITY
+    # https://docs.djangoproject.com/en/dev/ref/settings/#secure-proxy-ssl-header
+    SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
     # https://docs.djangoproject.com/en/dev/ref/settings/#secure-ssl-redirect
     SECURE_SSL_REDIRECT = env.bool("DJANGO_SECURE_SSL_REDIRECT", default=True)
     # https://docs.djangoproject.com/en/dev/ref/settings/#session-cookie-secure