Fix unlinking objects with should_delete=False after 75f8e75

It was keeping a reference to that object in IfcStore which could lead to issues.

src/blenderbim/blenderbim/bim/module/root/operator.py

@@ -268,6 +268,8 @@ class UnlinkObject(bpy.types.Operator):
 
                 obj = obj_copy
                 obj.name = object_name
+            elif element:
+                tool.Ifc.unlink(element)
 
             tool.Root.unlink_object(obj)
             for collection in obj.users_collection: