tor_addr_is_public_for_reject should return 0 for multicast addresses
This makes the treatment of addresses from other sources consistent with the implementation of get_interface_address6_list.
This might need to be cherry-picked to:
* legacy/trac#17027 (0.2.7)
* legacy/trac#17610 (0.2.6)
But only once their implementations include tor_addr_is_public_for_reject.
issue