[datafeed] Set headers parameter to an empty dict in DataFeedParser.retrieve_url
This parameter is then passed to urllib2.Request, which expects a dict and
won't check for None.
Closes #4842333.
#! /bin/sh -e
case "$1" in
remove)
if [ -x "/etc/init.d/cubicweb-ctl" ]; then
invoke-rc.d cubicweb-ctl stop || true
fi
;;
esac
#DEBHELPER#
exit 0