Merge branch 'jc/branch-in-use-error-message'

"git branch -f X" to repoint the branch X said that X was "checked out" in another worktree, even when branch X was not and instead being bisected or rebased. The message was reworded to say the branch was "in use". * jc/branch-in-use-error-message: branch: update the message to refuse touching a branch in-use