Fixed: FS#3032 - dovecot: master: Warning: /var/www/clients/client20/web36/log is no longer mounted. If this is inten

the path for the dkim-keys is automaticly creaed by the server-plugin, the path could be empty in the interface, and the amavis-template for gentoo was updated

- Use it like $app->conf('yourpluginname', 'config-key', 'value')
- omit the value to read the config value, provide it to set the value

- Important for plugin files!