[dataimport] Add safety belt on "gen_rtype" in MetaGenerator, closes #3712892 Some cubes may well add to the META_RTYPES set, hence crashing the gen_<somecubemeta> call.

#! /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