The markup for favicon `<img>` element in feed item used `src` instead of
`ng-src`, causing browser to make broken requests for
`.../apps/news/%7B%7B%20::Content.getFeed(item.feedId).faviconLink%20%7D%7D`
Changing the attribute to `ng-src` fixed that.
Signed-off-by: mormegil <mormegil@centrum.cz>
