On MAC spoofing failure, include the name of the disabled network card in the...

On MAC spoofing failure, include the name of the disabled network card in the title of the notification

That was the intention since 988b4186
but in that commit, we forgot to replace gettext with eval_gettext
when introducing variables in the translatable string. Let's fix this
and accordingly, drop the test suite workaround for this bug.

refs: #17784