open_basedir contains client0 where it should contain client1 when value is taken from System default

ISPConfig 3.1b2

I added a couple of paths to PHP's open_basedir default (under Server Config -> PHP Settings -> PHP open_basedir):

[website_path]/web:[website_path]/private:[website_path]/tmp:/var/www/[website_domain]/web:/srv/www/[website_domain]/web:/usr/share/php5:/usr/share/php:/tmp:/usr/share/phpmyadmin:/etc/phpmyadmin:/var/lib/phpmyadmin:/usr/local/zend/var/zray/extensions:/usr/local/zend/share:/usr/local/zend/var/plugins

When I edit an existing website and empty the PHP open_basedir field, to let ISPConfig fill it with the default value (as defined above), the resultant string contains client0, instead of client1:

/var/www/clients/client0/web1/web:/var/www/clients/client0/web1/private:/var/www/clients/client0/web1/tmp:/var/www/webdev3.example.com/web:/srv/www/webdev3.example.com/web:/usr/share/php5:/usr/share/php:/tmp:/usr/share/phpmyadmin:/etc/phpmyadmin:/var/lib/phpmyadmin:/usr/local/zend/var/zray/extensions:/usr/local/zend/share:/usr/local/zend/var/plugins

The values at the top of the page indicate that indeed the client is 1:

Linux User
   web1
Linux Group
   client1