Update Debianization from 0.6 branch
Update changelog
LISTEN_FDS specifies number of passed sockets, not the first available fd
Don't call listen(3) on systemd sockets, already done
Add systemd unit
Fix checking for error in systemd_get_socket
Rename variable to decrease confusion
Merge pull request #58 from dottedmag/master

systemd unit for rspamd (and associated fixes)