swServer_signal_handler: Fatal Error: manager process exit. status=0, signal=11

[hhxsv5]

Please answer these questions before submitting your issue. Thanks!

1. What did you do? If possible, provide a simple script for reproducing the error.
   addProcess创建一个inotify进程，监控代码变化以便reload。第二次reload时会出现如题的错误，并提示警告Warning: Swoole\Server::reload(): failed to send the reload signal. Error: No such process[3]

2. What did you expect to see?
   没有错误和警告，正常reload

3. What did you see instead?
   出现错误，无法reload

4. What version of Swoole are you using (show your php --ri swoole)?
   4.2.8

5. What is your machine environment used (including version of kernel & php & gcc) ?
   PHP 7.1.21
   gcc version 4.9.2 (Debian 4.9.2-10+deb8u1)
   Debian GNU/Linux 8 \n \l

[hhxsv5]

经测试Swoole 4.2.7无此问题