message: fix co::exec
diff: @@ -1221,22 +1221,30 @@ int swoole_shell_exec(char *command, pid_t *pid, uint8_t get_error_stream)
  if ((child_pid = fork()) == -1)
  {
  swSysError("fork() failed.");
  + close(fds[0]);
  + close(fds[1]);
  return SW_ERR;
  }
  if (child_pid == 0)
  {
  close(fds[SW_PIPE_READ]);
  +
  + if (fds[SW_PIPE_WRITE] != 1) {
  dup2(fds[SW_PIPE_WRITE], 1);
  + }
  +
  if (get_error_stream)
  {
  + if (fds[SW_PIPE_WRITE] != 2) {
  dup2(fds[SW_PIPE_WRITE], 2);
  }
  + }
  +
  + close(fds[SW_PIPE_WRITE]);
  - //Needed so negative PIDs can kill children of /bin/sh
  - setpgid(child_pid, child_pid);
  - execl("/bin/sh", "/bin/sh", "-c", command, NULL);
  - exit(0);
  + execl("/bin/sh", "sh", "-c", command, NULL);
  + exit(127);
  }
  else
  {
  