UI: Branch input placeholder no longer suggests master branch

[sean-morris]

The placeholder that indicated a default branch name is removed from the
branch field and the message instructing the user as to how the branch
name is handled is updated

[consideRatio]

This LGTM. The CircleCI error says it didn't detect a .circleci/config.yml, this is just weird and I'm ignoring it.

[welcome]

Congrats on your first merged pull request in this project! 🎉

Thank you for contributing, we are very proud of you! ❤️

[consideRatio]

@sean-morris oooooooooooh this was a PR to gh-pages, I wonder if that should be done to the main branch instead and then the gh-pages branch is automatically updated.

[consideRatio]

@sean-morris yepp, see the commit history of the gh-pages branch. It is built and updated automatically. Can you find the source code that you should change that give rise to this in the main branch and update it there?

See https://github.com/jupyterhub/nbgitpuller/commits/gh-pages for an indication of this btw.

I'm not sure if I caused an issue merging this, but I think I didn't. It should be updated in the main branch though because otherwise i think it will be overridden on next PR merged.