#3393 fix missing sub-url prefix in relative avatar link

models/pull.go

@@ -246,7 +246,7 @@ func (pr *PullRequest) Merge(doer *User, baseGitRepo *git.Repository) (err error
 		Sender: &api.PayloadUser{
 			UserName:  doer.Name,
 			ID:        doer.ID,
-			AvatarUrl: setting.AppUrl + doer.RelAvatarLink(),
+			AvatarUrl: doer.AvatarLink(),
 		},
 	}
 	if err = PrepareWebhooks(pr.BaseRepo, HOOK_EVENT_PUSH, p); err != nil {