[multi-sources-removal] Drop the "true" multi-sources planner
Only keep copy-based sources. This will soon allow for greater code
simplification.
Related to #2919300
#! /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
fi
fi
#DEBHELPER#
exit 0