chore: explicitly handle undefined case

Author: baileympearson

src/sdam/topology.ts

@@ -909,13 +909,12 @@ function processWaitQueue(topology: Topology) {
       const server1 = topology.s.servers.get(selectedDescriptions[0].address);
       const server2 = topology.s.servers.get(selectedDescriptions[1].address);
 
-      if (server1?.s.operationCount === server2?.s.operationCount) {
-        selectedServer = Math.floor(Math.random() * 2) === 0 ? server1 : server2;
-      } else {
-        selectedServer =
-          server1 && server2 && server1.s.operationCount < server2.s.operationCount
-            ? server1
-            : server2;
+      if (server1 && server2) {
+        if (server1.s.operationCount === server2.s.operationCount) {
+          selectedServer = Math.floor(Math.random() * 2) === 0 ? server1 : server2;
+        } else {
+          selectedServer = server1.s.operationCount < server2.s.operationCount ? server1 : server2;
+        }
       }
     } else {
       const descriptions = shuffle(selectedDescriptions, 2);