There's a review request open on mentors.debian.net now: https://mentors.debian.net/package/network-manager-fortisslvpn
The up-to date version of the package is available here: https://mentors.debian.net/debian/pool/main/n/network-manager-fortisslvpn/ Download the package with dget using this command: dget -x https://mentors.debian.net/debian/pool/main/n/network-manager-fortisslvpn/network-manager-fortisslvpn_1.2.6-1.dsc
