the client is calling cleanup() on this challenge type too

trustify/client/payment_challenge.py

@@ -18,6 +18,10 @@ class Payment_Challenge(Challenge):
         self.reason = reason
         self.times_performed = 0
 
+    def cleanup(self):
+        # Currently, payment challenges do not appear to require any cleanup.
+        pass
+        
     def perform(self, quiet=True):
         if quiet:
             dialog.Dialog().msgbox(self.get_display_string(), width=70)