Revert "Temporarily disable use of sqlite db for autopkgtests"

The database has been regenerated, so let's switch back to using
it to speed up britney.

This reverts commit e0fb5d8816.

britney.conf

@@ -104,7 +104,7 @@ ADT_SWIFT_URL     = https://objectstorage.prodstack5.canonical.com/swift/v1/AUTH
 # Base URL for autopkgtest site, used for links in the excuses
 ADT_CI_URL        = https://autopkgtest.ubuntu.com/
 # URL for the autopkgtest database, if used
-#ADT_DB_URL        = https://autopkgtest.ubuntu.com/static/autopkgtest.db
+ADT_DB_URL        = https://autopkgtest.ubuntu.com/static/autopkgtest.db
 ADT_HUGE          = 20
 
 # Autopkgtest results can be used to influence the aging