Preinstall warning about major upgrades: Also mention 14.9
Summary
Our current upgrade-check.rb
may lead customers who want to upgrade from pre-14.9 to 15 astray, because if they upgrade only to 14.10 first, they are likely to encounter these 14.9 migration problems
Proposal
Include a sentence (and/or code to focus it to applicable cases) that mentions https://docs.gitlab.com/ee/update/index.html#1490
.