Please re-produce this error by step:
1. Install Litespeed to CentOS 7
2. Create new listener with ANY & Graceful restart
3. Create new listener with special IP & Graceful restart
4. You will see error
5. Try to Graceful restart but error still happen
6. Login to SSH, use cmd: systemctl restatrt lshttpd.service, but error still happen
7. Reboot server => Litespeed work again