fix: browserActon icon in Chromium 80
fix: browserActon icon in Chromium 80

In past we used SVG in Firefox and if that threw an error (Chromium) we
falled back to PNG. Sadly something changed around Chromium 80 and the
icon was not properly set on Chromium (including Brave)

For now we just use PNG everywhere.

lidel/ipfs-firefox-addon,lidel/ipfs-firefox-addon,lidel/ipfs-firefox-addon