The thumbnail is not defined (on the GeoNode grid) when a dataset is uploaded through the plugin

[Gpetrak]

When we upload a dataset on GeoNode through the plugin, the thumbnail is not defined. In the dataset's grid of the GeoNode UI, it is presented as below:

while it should be presented as:

Of course the user is able to set the thumbnail through the GeoNode UI, but it should be already set during the upload.