A new version of sabnzbd was released a few days ago. Renaming the previous ebuild works here.
commit f4c17a208f85e95ac2f4b37d29d1dfe9931f9143 Author: Justin Bronder <jsbronder@gentoo.org> Date: Mon Sep 17 17:35:08 2018 -0400 net-nntp/sabnzbd: bump 2.3.5 Closes #665628. Thanks to Neil Bothwick for the report and testing. Package-Manager: Portage-2.3.40, Repoman-2.3.9