Fix the generic jpa exception thrown on persist
Fix the generic jpa exception thrown on persist

Constraints are not properly translated into exception, for example when we try to insert the same bucket/user twice. The solution has been to downgrade hsqldb lib to the previous version until it is fixed

gparanthoen/workflow-catalog,laurianed/catalog,ShatalovYaroslav/catalog,ow2-proactive/workflow-catalog,laurianed/workflow-catalog,laurianed/catalog,ow2-proactive/catalog,ow2-proactive/catalog,ow2-proactive/catalog,paraita/workflow-catalog,laurianed/catalog,yinan-liu/workflow-catalog,ShatalovYaroslav/catalog,ShatalovYaroslav/catalog