fix change that broke the htmllib tests
diff --git a/Lib/sgmllib.py b/Lib/sgmllib.py
index 5c59a5c..194396b 100644
--- a/Lib/sgmllib.py
+++ b/Lib/sgmllib.py
@@ -424,11 +424,11 @@
 
     def handle_entityref(self, name):
         """Handle entity references, no need to override."""
-        replacement = convert_entityref(name)
+        replacement = self.convert_entityref(name)
         if replacement is None:
             self.unknown_entityref(name)
         else:
-            self.handle_data(convert_entityref(name))
+            self.handle_data(self.convert_entityref(name))
 
     # Example -- handle data, should be overridden
     def handle_data(self, data):