[hooks/syncschema] do not crash on double removal of a constraint Some complicated migrations may entail a double constraint removal. It is not yet known whether this is a genuine cw bug or the result of a complicated migration story, but we should nevertheless not crash. Rather, emit a CRITICAL warning and proceed. Closes #3595309.

.. -*- coding: utf-8 -*-
 
Dernières modifications
-----------------------

* la table des `derniers changements`_ fournit un exemple d'utilisation de RQL
  pour récupérer les derniers changements ayant eu lieu sur ce site.

.. _`derniers changements`: view?rql=Any+M%2CX+WHERE+X+modification_date+M+ORDERBY+M+DESC+LIMIT+30