Explicitly point WMF OIT address space to ulsfo

Wikimedia headquarters' new IP space is not yet geolocated by MaxMind
properly, which means that it's currently being served by eqiad.

Make an exception from our general rule and explicitly point it to
ulsfo, similar to what we do for our own datacenters.

Change-Id: I3e2a8467257b59798fa5505cde8e5458c56921ea