Don't trigger on Chromium

[LoganDark]

I don't know if it's possible to detect this, but Chromium probably shouldn't trigger this banner, since you don't know if the user is using a fork that strips out WEI.

[lordfeck]

I'll see whether ungoogled chromium will include WEI or not. While it will be commendable if custom builds strip out WEI, it will be tricky to detect unless the Chromium derivatives use their own UA strings or have something flagged in the navigator namespace.