Removing remote branch on Diffusion

I have problem to remove the remote branch in the phab/diffusion. When I try to execute command:

git push -d origin <branch_name>

I encountered the error from the ‘evil dragon’ something like:
Edit the repository configuration before making dangerous changes.

Are there some steps I can follow to properly remove ?

I noticed the remote repo has setting, ‘allow dangerous changes’ is disabled. I wonder if this is the reason.