Save a bit of bandwidth by only requesting 3-times the rendered avatar
size. Factor 4 is only really beneficial on a handful of mobile phones
and I don't think they are the primary device we design for.
Configurability contributed by zeripath.
Fixes: https://github.com/go-gitea/gitea/pull/17422
Fixes: https://github.com/go-gitea/gitea/issues/16287
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
silverwind