Thumbnails don't include anymore OSM base layer

[capooti]

This was fixed by reverting to use wikimedia base layer, as per this ticket in GeoNode:
GeoNode#4509

I will update the configuration of CAMP accordingly.

[capooti]

Unfortunately there is still the bug in GeoNode:
GeoNode#4517

the service GeoNode uses for providing base layers in GeoNode raises a 403