[Merge] lp:~ricmm/goget-ubuntu-touch/no-legacy-subarches into lp:goget-ubuntu-touch

[Sergio Schvezov]

Review: Needs Fixing

A regex might be better here in case we ever create a new arch with generic.

Also, why isn't this implemented in isLegacy?
-- 
https://code.launchpad.net/~ricmm/goget-ubuntu-touch/no-legacy-subarches/+merge/277386
Your team Ubuntu Phablet Team is subscribed to branch lp:goget-ubuntu-touch.