the secret agent object
the connection for which secrets were to be saved, note that this object will be unrefed after the callback has returned, use g_object_ref()/g_object_unref() if you want to use this object after the callback has returned
if the saving secrets failed, give a descriptive error here
Called as a result of a request by NM to save secrets. When the #NMSecretAgent subclass has finished saving the secrets, this function should be called.