Drop 3.13 incomplete backward compat in edit controller. It is very old and broken (there is another non-backward-copmpatible usage of `_cw_entity_fields`), better to remove it instead of fixing. Closes #3515223.

#!/bin/sh -e
if [ "$1" = "purge" ] ; then
        update-rc.d cubicweb remove >/dev/null
fi
 
#DEBHELPER#
 
exit 0