Updating to RoundCube 1.2.9 on Ubuntu 16.04

As you know, on Ubuntu 16.04, Roundcube version is 1.2 beta; and Enigma plugin does not work.
Here is the solution.

1. apt-mark hold roundcube*
   ln -s /etc/roundcube/ /usr/share/roundcube/config
   cd /usr/local/src/
   wget https://github.com/roundcube/roundc...oad/1.2.9/roundcubemail-1.2.9-complete.tar.gz
   chown -R root:root roundcubemail-1.2.9
   cd roundcubemail*
   ./bin/installto.sh /usr/share/roundcube/
   Set this directory and its sub-directory /usr/share/roundcube/plugins/enigma/home/ to www-data:www-data 0700
   Set all the files under this directory to www-data:www-data 0600
   
   
2. Edit file /etc/roundcube/plugins/enigma/config.inc.php so that:
   $config['enigma_keygen_server'] = true;

Finish. Create a new Enigma key pair inside Roundcube and see what happens.