Support importing older scale audio feedback components.

Skip importing properties for components if they don't have any.
Older scale audio feedback components didn't have component properties and were just the name and an empty string.

addons/io_hubs_addon/components/hubs_component.py

@@ -123,9 +123,10 @@ def gather(self, export_settings, object):
     @classmethod
     def gather_import(cls, gltf, blender_host, component_name, component_value, import_report, blender_ob=None):
         component = import_component(component_name, blender_host)
-        for property_name, property_value in component_value.items():
-            assign_property(gltf.vnodes, component,
-                            property_name, property_value)
+        if component_value:
+            for property_name, property_value in component_value.items():
+                assign_property(gltf.vnodes, component,
+                                property_name, property_value)
 
     def post_export(self, export_settings, host, ob=None):
         '''This is called by the exporter after the export process has finished'''