bridge users who configure the non-canonical address of a bridge switch to its canonical address
If I run a bridge with
Address 188.8.131.52 ORListenAddress 184.108.40.206
and then somebody runs their Tor client with
then it will connect, fetch the bridge descriptor, try to build a circuit by using 220.127.116.11, fail, and then sit there circuitless and bridgeless.
This bug is important because it means if you run a multihomed bridge, all the clients will immediately switch to using its single canonical address, ignoring all the other addresses you configured. If that canonical address gets blocked, the other addresses don't matter even if they'd still work.