.gitconfig: Remove `push.default`
.gitconfig: Remove `push.default`

This was causing issues on servers that don’t have an up-to-date Git installation. As a workaround, I decided to remove this from `.gitconfig` and add this to `~/.extra` for my laptop only:

    git config --global push.default simple

busayo/dotfiles,unicodeveloper/dotfiles,unicodeveloper/dotfiles,busayo/dotfiles