[Merge] ~lamoura/update-notifier:show-only-esm-infra-alerts-on-esm-machine into update-notifier:master

[Lucas Albuquerque Medeiros de Moura]

Brian, also we could have named exceptions here, but I don't know if that is an overkill for the script
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https://code.launchpad.net/~lamoura/update-notifier/+git/update-notifier/+merge/402163
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