-Fix issue 4416

See [issue 4987](https://github.com/diaspora/diaspora/issues/4987) and [4416](https://github.com/diaspora/diaspora/issues/4416)
@jhass or use another render: https://github.com/vmg/redcarpet/blob/340efa531e669b5e532781e906789ae5cf98562d/test/html_render_test.rb#L87