I forked a repository as a starting point for a new project, never intending to submit pull requests to the original repo. It's become annoying to have to select my own master branch every time I want to merge a branch in the GitHub interface.
How can I remove the reference to the upstream so that my own master branch will be automatically selected when creating merge requests?
I tried editing
.git/config as suggested here, but my config file does not include any reference to the upstream.