This bug was fixed in the package update-notifier - 3.168.10
--------------- update-notifier (3.168.10) xenial; urgency=medium
[ Julian Andres Klode ] * Do not notify-reboot-required on linux-image-extra removal (LP: #1458204)
-- Balint Reczey <email address hidden> Fri, 07 Dec 2018 11:14:24 +0100
This bug was fixed in the package update-notifier - 3.168.10
---------------
update-notifier (3.168.10) xenial; urgency=medium
[ Julian Andres Klode ] reboot- required on linux-image-extra removal (LP: #1458204)
* Do not notify-
-- Balint Reczey <email address hidden> Fri, 07 Dec 2018 11:14:24 +0100