[schema] restore constraint checking when running on old sqlite Old sqlite3 doesn't provide CHECK constraint names in error messages, preventing us from translating a backend integrity error into a ValidationError. This was added in 2012, but the sqlite3 version in RHEL6 is older; so if we run on old sqlite, keep checking the constraints in python rather than only in SQL. Closes #10927494

.. _rset_module:

:mod:`cubicweb.rset`
====================

.. automodule:: cubicweb.rset

    .. autoclass:: ResultSet
        :members: