better exit check

Author: mydea

dev-packages/node-overhead-gh-action/lib/getOverheadMeasurements.mjs

@@ -44,7 +44,7 @@ async function startAppProcess(cmd) {
   });
 
   appProcess.on('close', code => {
-    if (code !== 0) {
+    if (code && code !== 0) {
       rejectAppClose(new Error(`App process exited with code ${code}`));
     } else {
       resolveAppClose();