[predicates] keep making `yes` predicate importable from cubicweb (closes #2790319)
The `yes` predicate was moved out in CubicWeb 3.15 but it should have
remained importable from the cubicweb.predicates module, for bw compat
reasons and also because logilab.common.registry is an implementation
detail.
#! /bin/sh -e
case "$1" in
purge)
rm -rf /etc/cubicweb.d/
rm -rf /var/log/cubicweb/
rm -rf /var/lib/cubicweb/
;;
esac
#DEBHELPER#
exit 0