FIX: backrefs attribute may contain Entities

src/caoscrawler/identifiable_adapters.py

@@ -101,7 +101,10 @@ class IdentifiableAdapter(metaclass=ABCMeta):
         if ident.record_type is not None:
             query_string += ident.record_type
         for ref in ident.backrefs:
-            query_string += (" WHICH IS REFERENCED BY " + str(ref) + " AND")
+            eid = ref
+            if isinstance(ref, db.Entity):
+                eid = ref.id
+            query_string += (" WHICH IS REFERENCED BY " + str(eid) + " AND")
 
         query_string += " WITH "