Peertube users avatars optimization (Fix #303): * avoid multiple parallel request to load same avatar from Peertube * send "item-not-found" stanza when no avatar, instead of a vCard without avatar
Peertube users avatars optimization (Fix #303): * avoid multiple parallel request to load same avatar from Peertube * send "item-not-found" stanza when no avatar, instead of a vCard without avatar