DCO is enabled, so you need to add extra information in your commit messages from now on.
Or append -s flag in your commit command,
For more details, please refer to https://github.com/probot/dco.
Software Engineer, CNA, VMware R&D
Addr: 8F Tower C, Raycom Info Tech Park, No. 2 Kexueyuan South Road Haidian District, Beijing 100738 China