redmine git commit links point to external cgit

The redmine git browser is slow. Would be nice if we could get have the links to git commits in redmine to point to external git site with cgit.
http://git.alpinelinux.org/cgit/aports/

Issues there are referenced back to redmine. See forexample the “fixes #315” in commit message: http://git.alpinelinux.org/cgit/aports/commit/?id=a3041b9cb7ed70bb5894ef4d909d7bd7781fa691

(from redmine: issue id 321, created on 2010-03-11, closed on 2011-07-20)