Set Nasqueron logo as API domain favicon

Summary:
The Nasqueron private Docker registry API published a favicon, but
it makes more sense to host it at the root domain.

This changes recovers this favicon.

This is a follow-up for 16138497d33a.

Test Plan: Browse https://api.nasqueron.org

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D1877