Data from dump not working.

Hi.
I think variables "$vnstat_bin" and "data_dir" in config should be default commented (or ='').
In vnstat.php in function get_vnstat_data:
 if (!isset($vnstat_bin) || $vnstat_bin == '')
should be inverted to:
 if (isset($vnstat_bin) && $vnstat_bin != '')
(If we have set location of dump get data from file)
