[migration] don't crash when deleting a non-existing rtype When asked to delete a relation type, instead of checking if it was computed or not, just delete both the CWRType and CWComputedRType.

#! /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