Fix Ubuntu version needed to use tails-installer
sorry, but there is a mistake in the new installation assistant leading some Ubuntu users to send me bug reports and inquiries about tails-installer in Trusty:
“Ubuntu 14.04 (Trusty) or later in a PPA (Personal Package Archive)”
Unfortunately that is wrong. The installer is available only from Ubuntu Wily or Xenial, because Trusty lacks a recent version of syslinux.