Fedora 18 changes the way how to work with services in spec files. It introduces new macros - %systemd_post, %systemd_preun and %systemd_postun; which replace scriptlets from Fedora 17 and older (see https://fedoraproject.org/wiki/Packaging:ScriptletSnippets#Systemd, https://bugzilla.redhat.com/show_bug.cgi?id=850016).
This is fixed. -> https://github.com/pjps/ndjbdns/commit/bf2fa309e2be7e49304c5dd010a94a613ec2905f closing this bug. Please reopen it or file a new bug in case you spot any amiss. Thank you.