emergingthreats: create new package for surricata
This package should contain https://rules.emergingthreats.net/open/suricata/emerging.rules.tar.gz since it's used in ludus https://github.com/stratosphereips/Ludus/blob/master/install.py#L65
Related to issue https://gitlab.labs.nic.cz/turris/turris-os-packages/issues/358