Fix Table objects in common fields
This fixes the problem of putting and tables on common_fields and having lazy_define_table throw an exception because Table doesn't have a clone attribute.
@@ -593,7 +593,7 @@ class DAL(with_metaclass(MetaDAL, Serializable, BasicStorage)):
args_get = args.get
common_fields = self._common_fields
if common_fields:
- fields = list(fields) + [f.clone() for f in common_fields]
+ fields = list(fields) + [f if isinstance(f, Table) else f.clone() for f in common_fields]
table_class = args_get('table_class', Table)
table = table_class(self, tablename, *fields, **args)
