[migration/3.21] idempotency fixes
Drop constraints before (re)creating them
This is postgresql-specific syntax, sqlserver needs work.
#! /bin/sh -e#if [ "$1" = configure ]; then if which install-docs >/dev/null 2>&1; then install-docs -i /usr/share/doc-base/cubicweb-doc fifi#DEBHELPER#exit 0