After VPS restart, it started to show in WHM/cpanel:

Trial License

This copy of cPanel & WHM is for trial use and will expire at the end of the trial period. You will need to upgrade to a paid copy of cPanel & WHM to continue using the software after that period.

In my case i hidden it by editing files in /etc/sysconfig/network-scripts/

First backup and remove ifcfg-venet0:1:
zip ifcfg-venet0:1;mkdir bckp;mv bckp
replacing my secondary IP by my primary VPS IP in file /etc/sysconfig/network-scripts/ifcfg-venet0:0
vi /etc/sysconfig/network-scripts/ifcfg-venet0:0
and maybe change IP in ifcfg-venet0:1 too

Then i restart network by command:
service network restart
Then did WHM key update by command:
- Try add ip on WHM / IP functions / Add IP ?
- make sure WHM VPS has its IP assigned on openvz server / re-add it, then restart network on vps