Merge pull request #5 from ami-iit/fix-no-visual

Skip importing models with no visuals

src/blend_my_bot/model_importer.py

@@ -85,6 +85,8 @@ def import_links(
         )
         for link_id in range(model_geometry.getNrOfLinks()):
             link_name = model_geometry.getLinkName(link_id)
+            if visuals[link_id] == ():  # no visual
+                continue
             link_visual = visuals[link_id][0]
             if link_visual.isExternalMesh():
                 mesh_path = (