phabricator: Set base-uri to https for labs

Since phabricator does not use protocol relative URLs,
https renders without css or js without this change. This forces
phab to always use https for those things.

Change-Id: I1990d37f007337ec3479b6908aaf73020cd5e3a4
Merge "phabricator: Set base-uri to https for labs" into production