Since git-flow just wraps regular git functionality, how about simply deleting the new branch (assuming you have no changes in there you want saved)?
$ git checkout masterSwitched to branch 'master'$ git branch -d feature/your-feature-name-here
Or just use git-flow:
git flow feature delete your-feature-branch
Note that the feature/ prefix is omitted when using this command
feature/
git hf feature cancel -f
Use git hf help and git hf feature help to see the possibilities.
git hf help
git hf feature help