api: do not expect any return value in callbacks change/delete of config_new_option (scripting API)

tests/scripts/python/testapi.py

@@ -181,12 +181,12 @@ def option_check_value_cb(data, option, value):
 
 def option_change_cb(data, option):
     """Option change callback."""
-    return 1
+    pass
 
 
 def option_delete_cb(data, option):
     """Option delete callback."""
-    return 1
+    pass
 
 
 def test_config():

tests/scripts/python/unparse.py

@@ -1090,7 +1090,7 @@ class UnparseGuile(UnparsePython):
 
     def _ast_pass(self, node):
         """Add an AST Pass in output."""
-        pass
+        self.add('#t')
 
     def _ast_return(self, node):
         """Add an AST Return in output."""