[Merge] lp:~azzar1/update-manager/fix-lp-1805118 into lp:update-manager

[Andrea Azzarone]

The proposal to merge lp:~azzar1/update-manager/fix-lp-1805118 into lp:update-manager has been updated.

Commit message changed to:

self.button_settings can be None in case update-manager is running in a distribution that does not ship software-properties-gtk. Do not show the canonical-livepatch reminder if self.button_settings is None.

For more details, see:
https://code.launchpad.net/~azzar1/update-manager/fix-lp-1805118/+merge/359621
-- 
Your team Ubuntu Core Development Team is requested to review the proposed merge of lp:~azzar1/update-manager/fix-lp-1805118 into lp:update-manager.