cubicweb #2094544 syncschema hooks don't use sql_current_date / timestamp [resolved]

this causes failures when adding a column with a default value set to TODAY / NOW on sql server.

This patch needs lgdb 1.8.1

priorityimportant
typebug
done in3.14.1
load left0.000
closed by#7e0d1fb1092d use dbhelper functions to get default date / datetime (closes #2094544)