Add Chromium to known browsers

[wardal]

Accidentally found that for Chromium in Ubuntu script show out-of-date message, as unknown browser. Needed to add isUnknownBrowserOK to true, to hide message.

Chromium Version 77.0.3865.90 (Official Build) Built on Ubuntu , running on Ubuntu 16.04 (64-bit)

[wardal]

I found this: #64
so maybe will update readme soon.