fix(replset): correct server leak on initial connect

Author: mbroadst

lib/core/topologies/replset.js

@@ -378,6 +378,7 @@ function connectNewServers(self, servers, callback) {
       // Command Monitoring events
       relayEvents(server, self, ['commandStarted', 'commandSucceeded', 'commandFailed']);
 
+      self.s.connectingServers.push(server);
       server.connect(self.s.connectOptions);
     }, i);
   }