Add exception filter for _sqlite_dupe_key_error

We can get 'PRIMARY KEY must be unique' error on some
platforms and versions of sqlite library while trying to
insert the row with the same primary key that already exist.
In this case oslo.db should raise DBDuplicateEntry error.
Add corresponding filter to _sqlite_dupe_key_error

Closes-Bug: #1386145

Change-Id: Ifafd6a8e0b613a31e596043071aef4d410a976f2
Merge "Add exception filter for _sqlite_dupe_key_error"