TBAN timed channel bans (auto-lift on the tick)

src/ircd.rs

@@ -353,6 +353,7 @@ impl Ircd {
     fn on_tick(&mut self) {
         self.server.ping_links(); // keepalive on every server link
         self.server.purge_xlines(); // drop expired server bans
+        self.server.purge_tbans(); // lift expired timed channel bans (TBAN)
         let now = crate::server::now();
         let (to_ping, to_quit) = self.server.idle_check(now);
         for uid in to_ping {