Fix memleak bug reported on Zope list. This is instead of moving from Secret...

Fix memleak bug reported on Zope list.  This is instead of moving from Secret Lab's development release of xmlrpclib (0.9.9).

lib/python/xmlrpclib.py

@@ -217,7 +217,7 @@ if sgmlop:
             try:
                 self.parser.close()
             finally:
-                self.parser = None # nuke circular reference
+                self.parser = self.feed = None # nuke circular reference
 
         def handle_entityref(self, entity):
             # <string> entity