I've tested alf-redyoung's change above against update-notifier 3.168.3 (Ubuntu 16.04) for a few days and it seems to fix the bug. Submitting it as a patch.
I've tested alf-redyoung's change above against update-notifier 3.168.3 (Ubuntu 16.04) for a few days and it seems to fix the bug. Submitting it as a patch.