进入settings=>repository=>protected branches里，修改Allowed to push为Developers + Maintainers 或者直接点击Unprotect.
developer权限也可提交代码
master分支下修改了文件，计划push，发现没有权限
remote: GitLab: You are not allowed to push code to protected branches on this project. ! [remote rejected] master -> master (pre-receive hook declined)
修改文件并添加
git add .
git commit -m "m"
git checkout -b update_fastjosn_version //新建分支
git push //此处提示错误
git push --set-upstream origin update_fastjson_version //再次OK了
可以看到push成功了，再登陆gitlab，新建一个merge request就行了，让有merge权限的人merge一下。