The maintainer didn't just make a simple fork. He renamed it, bought a domain, all behind the owners back while he's on vacation.
From an etiquette standpoint, I wouldn't want to work with a maintainer who just hijacks projects. Based on the behavior I've seen, I'm saddened to see this.
This project's contributors are Chinese: https://github.com/gogits/gogs/graphs/contributors. The gross majority of the commits come from a few people - the project has been around for years. And over a period of a few weeks, this happened, by an outsider.
They are probably gfw'd and have difficulty finding a VPN.