versions pulldown lists many unavailable versions

[efahl]

See what I'm talking about here:

firmware-selector-openwrt-org/www/index.js

Line 828 in ea04cec

const unsupported_versions_re = /^(19\.07\.\d|18\.06\.\d|17\.01\.\d)$/;

This is mostly a placeholder for moving the supported versions processing up to the ASU server, since it's already doing the work (but not exposing it) and the server is the true authority as to what can actually be built.

Will proceed with a PR once we get something done in the server:
openwrt/asu#1577

[mwarning]

Less hacks. 👍