django 4 support: Adapt production settings for memcached changes
This adapts the memcached import the same way the swh.web module did.
Follow up on 4698e8c9
I currently have issues on pod otherwise:
do-migration raise InvalidCacheBackendError(
do-migration django.core.cache.backends.base.InvalidCacheBackendError: Could not find backend 'django.core.cache.backends.memcached.MemcachedCache': Module "django.core.cache.backends.memcached" does not define a "MemcachedCache" attribute
/class
Edited by Antoine R. Dumont