[1.8.x] Allowed using the sqlite3 backend as much as possible without _sqlite3.
[1.8.x] Allowed using the sqlite3 backend as much as possible without _sqlite3.

The inner import was dropped during the reorganizing of the database
backends in commit 28308078f397d1de36fd0da417ac7da2544ba12d.

Backport of 95058606c89ba2dc95205487fa837ec39cf41ed5 from master

pquentin/django,h4r5h1t/django-hauthy,pquentin/django,h4r5h1t/django-hauthy,h4r5h1t/django-hauthy,pquentin/django,h4r5h1t/django-hauthy