[trac714] review comment

src/lib/python/isc/config/cfgmgr_messages.mes

@@ -24,7 +24,8 @@ are now applied, and no action from the administrator is necessary.
 The configuration manager sent a configuration update to a module, but
 the module responded with an answer that could not be parsed. The answer
 message appears to be invalid JSON data, or not decodable to a string.
-This is likely to be a problem in the module in question.
+This is likely to be a problem in the module in question. The update is
+assumed to have failed, and will not be stored.
 
 % CFGMGR_CC_SESSION_ERROR Error connecting to command channel: %1
 The configuration manager daemon was unable to connect to the messaging