[migration] fix bug in `CWAttributeAddOp.revertprecommit_event`
The `rdefdef` attribute is set during the operation execution. In some the
operation crash before this assignment. In such case `revertprecommit` raise an
attribute error crashing the whole process and shadowing the original error.
This changeset detect and Avoid this situation.
#! /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