-Fix issue 4416

See [issue 4987](https://github.com/diaspora/diaspora/issues/4987) and [4416](https://github.com/diaspora/diaspora/issues/4416)
I guess then it's time to replace all URI.extract calls and all autolinking (redcarpet's and rails_autolink) with [twitter-text-rb](https://github.com/twitter/twitter-text-rb) which doesn't seem to suffer from these issues.