Fix parsing of UC errors in sqlite 3.7.16+/3.8.2+

The new version of libsqlite changed the format of error messages.
Code of oslo.db helpers must be updated appropriately. This was meant
to be fixed by I86e9673ac409b3b3e881bea7cb8b3516f320388d, but that
change doesn't cope well with the new format of column names.

Closes-Bug: #1259915

Change-Id: Iec39c8804ea47307a98d1b79899ff74af9404bf6
Merge "Fix parsing of UC errors in sqlite 3.7.16+/3.8.2+"