Deploy script removes github pages custom domain

Created by: sylvainbannier

When using these to deploy to github :

git commit -am "Save local changes"
git checkout -B gh-pages
git add -f build
git commit -am "Rebuild website"
git filter-branch -f --prune-empty --subdirectory-filter build
git push -f origin gh-pages
git checkout -

Github loses the custom domain setting

Note : I think it's due to the -B option in git checkout -B gh-pages.