We've performed a preventive replacement of SSL certificates of Project Turris servers because of a serious OpenSSL bug. Certificates for the main site have already been replaced but we were not able to replace the certificate for server providing the packages yet due to an overload of CA's infrastructure. We strongly discourage from installing packages on your router manually (either using opkg or in LuCI interface), automatic updates of router are safe. We will issue another update after solving this issue.