[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
#

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