Clarify that timers never terminate

zebra-network/src/peer_set/initialize.rs

@@ -353,7 +353,7 @@ where
 
         let crawler_action = tokio::select! {
             a = handshakes.next() => a.expect("handshakes never terminates, because it contains a future that never resolves"),
-            a = crawl_timer.next() => a.expect("crawl_timer never terminates"),
+            a = crawl_timer.next() => a.expect("timers never terminate"),
             // turn the demand into an action, based on the crawler's current state
             _ = demand_rx.next() => {
                 if handshakes.len() > 50 {