Prevent NPE on avatar direct rendering if federated avatars disabled (#15434)
Prevent NPE on avatar direct rendering if federated avatars disabled (#15434)

#13649 assumed that direct avatar urls would always be libravatar urls - this leads
to NPEs if federated avatar service is disabled.

Fix #15421

Signed-off-by: Andrew Thornton <6a547fdd28db89120bdd70d4af1f9ba672ccd43a@cantab.net>

Co-authored-by: techknowlogick <274271a2414b6bd0d2eb0401dd4ff6e85d7016a7@gitea.io>
vdbt/gitea,go-gitea/gitea,cez81/gitea,vdbt/gitea,go-gitea/gitea,cez81/gitea,cez81/gitea,go-gitea/gitea