Thorium 2.4.x : on MacOS (probably other OS too) mouse click + mod keys on React router links in GUI trigger new blank window or download (e.g. localhost in dev, library_index.html in prod)

[danielweck]

@panaC we observed this in Thorium3 too, probably a React Router breaking change (event.preventDefault() handling). So, we can't fix this in 2.4.x but we have to make sure this doesn't happen in 3.x.x