fix(cluster): potential bug when cluster not available

Gareth Jones · Gareth Jones · commit f2f9790becae · 2017-12-12T08:32:35.000+11:00
diff --git a/lib/log4js.js b/lib/log4js.js
@@ -207,7 +207,9 @@ function configure(configurationFileOrObject) {
 
   // just in case configure is called after shutdown
   process.removeListener('message', receiver);
-  cluster.removeListener('message', receiver);
+  if (cluster) {
+    cluster.removeListener('message', receiver);
+  }
   if (config.disableClustering) {
     debug('Not listening for cluster messages, because clustering disabled.');
   } else if (isPM2Master()) {
