Provide a direct link to actual data for Monkey ECoG Tutorial

It is not clear which dataset this tutorial is designed to work with:

https://github.com/fieldtrip/website/blob/master/tutorial/monkey_ecog.md

It gives a link to the general ECoG page with data sets from 2 monkeys, and I think the data should be from K2 if you look at the surface map picture name (`tutorial/monkey_ecog/k2_1.png`). When trying a couple of the K2 monkey datasets I get:

```
Error using ft_datatype_raw (line 84)
inconsistent number of channels in trial 1

Error in ft_checkdata (line 268)
data = ft_datatype_raw(data, 'hassampleinfo', hassampleinfo);

Error in ft_redefinetrial (line 117)
data = ft_checkdata(data, 'datatype', {'raw+comp', 'raw'}, 'feedback', cfg.feedback);

Error in vdemo (line 57)
data_1 = ft_redefinetrial(cfg,data);
```

There is also a data set for this tutorial on the fieldtrip FTP, which does not work with the demo code either. Which data set should be used and I can then edit the link on the tutorial page...