BridgeDB should parse "a lines" from networkstatus-bridges
BridgeDB reads or-addresses from the bridge-descriptors, but should read them from the networkstatus-bridges instead.
The format of an "a" line in networkstatus-bridges is the same as the or-address line in bridge-descriptor, but has been verified as reachable by the bridge-authority.
I'm not sure what the status of ipv6 reachability testing is, or when "a" lines will appear in networkstatus-bridges.