Make the bridge authority reject private PT addresses when DirAllowPrivateAddresses is 0
When DirAllowPrivateAddresses is 0, the bridge authority should reject extra info descriptors with private addresses in their PT lines.
We should add some text asking operators to upgrade, and deploy this change after legacy/trac#31009 (moved) is backported,
Gaba, this ticket should go in the PT sponsor with legacy/trac#31009 (moved).