Summary:
The current default wordmark is "Phabricator" which is trademarked and the
default logo is also copyright.
(This change was made by @speck directly in the deployed instnace, bringing it into `master` now).
Test Plan: should be fine.
Reviewers: O1 Blessed Committers, speck
Reviewed By: O1 Blessed Committers, speck
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, speck
Differential Revision: https://we.phorge.it/D25048
