Moving Group-Office from it's default location
Edit /etc/apache2/sites-enabled/000-default and change:
Edit /etc/groupoffice/config.php and change the following value:
There might be a full_url property too. If it's there change it too.
Note: If you also installed the groupoffice-mailserver package and you're moving the main Group-Office installation, you need to update /etc/groupoffice/globalconfig.inc.php too. There's a variable $config['serverclient_server_url'] that points to the main Group-Office URL that needs to be updated.