[test, cw props] ensure we can't add user specific / system-wide properties
we had this pb on an historical instance in our intranet (eg. running
for about 8 years).
#! /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