I believe the mentioned file is appropriate for libnotify-bin and isn't appropriate for lxpanel package since lxpanel does not interact with the daemon directly.
And thank you for a notice about dependencies. Both libnotify-bin and notification-daemon are added as Recommended by lxpanel now. The original issue is probably related to #845555, so if current is missing from data then alarm will never go out. Fix for such case also pushed. Please, reopen this bug if issue still persists. Thank you very much.
