Make IPv6-only bridges work
This needs bridge guards (#7144 (moved) - so the bridge can connect via a dual-stack bridge guard to whatever guard the client has selected), and it needs IPv6 bridges to work in general (#4847 (moved)).
This needs bridge guards (#7144 (moved) - so the bridge can connect via a dual-stack bridge guard to whatever guard the client has selected), and it needs IPv6 bridges to work in general (#4847 (moved)).