[Koha] Koha 3.18.4 released

[Chris Cormack]

The Koha release team are proud to announce the release of Koha 3.18.4.
This release contains one security fix and users are recommended to upgrade
to this release.

You can either wait a day or 2 for the packages to be released, or you can
download the tarball at http://download.koha-community.org

Please read http://koha-community.org/koha-3-18-4-released/ for the release
notes

Chris