You can easily update your RoundCube to the latest version by using this command:
The latest version will also bring you the new RoundCube skin elastic.
If you skin is not set to elastic you can do it by yourself
- check that you have this folder: /usr/local/cwpsrv/var/services/roundcube/skins/elastic
- then run the command to set the elastic skin as default
sed -i "s/larry/elastic/g" /usr/local/cwpsrv/var/services/roundcube/config/config.inc.php