conflux, security: Reject a CONFLUX_LINK cell that arrives on a circuit
which already has attached streams. (boo#1275920, CVE-2026-77584, TROVE-2026-025)
client: Resume warning about unsafe socks protocols when SafeSocks
is not set. Also resume warning every time when TestSocks is set.
Make clients more consistently expire entry guards 48 to 60 days
after they are first used.