benchmark: http simple connect timeout on macOS

<!-- Thank you for reporting an issue. This issue tracker is for bugs and issues found within Node.js core. If you require more general support please file an issue on our help repo. https://github.com/nodejs/help Please fill in as much of the template below as you're able. Version: output of `node -v` Platform: output of `uname -a` (UNIX), or version and 32 or 64-bit (Windows) Subsystem: if known, please specify affected core module name --> * **Version**: v13.11.0 * **Platform**: macOS Catalina * **Subsystem**: benchmark ### What steps will reproduce the bug? <!-- Enter details about your bug, preferably a simple code snippet that can be run using `node` directly without installing third-party dependencies. --> ```js node benchmark/http/simple.js ``` ### How often does it reproduce? Is there a required condition? Always reproduces. ### What is the expected behavior? <!-- If possible please provide textual output instead of screenshots. --> It should run without timeout error on macOS. ### What do you see instead? <!-- If possible please provide textual output instead of screenshots. --> <img width="1121" alt="Screen Shot 2020-03-18 at 11 58 44 AM" src="https://user-images.githubusercontent.com/3114495/76924042-1d49f200-6910-11ea-8cb3-66dab5f4d8a6.png"> ### Additional information <!-- Tell us anything else you think we should know. --> I found that it works when I change `duration` from 5 to 10. It could be some problem with frequently port binding. ```js const bench = common.createBenchmark(main, { // Unicode confuses ab on os x. type: ['bytes', 'buffer'], len: [4, 1024, 102400], chunks: [1, 4], c: [50, 500], chunkedEnc: [1, 0], duration: 5 // replace with 10, it works }); ```