So, I will change the group to Apache. But I think this file also have write permission.
sudo chown apache:apache /var/www/html/owncloud/config/config.php
Serious question: Do you really want this?
OMG. It is solved now. I think this is the wrong owner issue.
I am looking the solution far away from this. But the solution is near me.
Thank you so much. I really appreciate it.