Let vdebug listen to all interfaces, not only localhost

While setting up Xdebug on a Vagrant development environment I encountered a problem. Xdebug couldn't connect back to vdebug. I first thought it had to do with the configuration of the host only adapter, but it appeared to be that vdebug listens only to localhost default ( https://github.com/joonty/vdebug/blob/9f68dbcd8e44219ae562f62f83cf709a687d045e/plugin/vdebug.vim#L88 ).

So, to let vdebug listen to incoming requests at all interfaces, add the following to your vimrc:

let g:vdebug_options = {
    \ 'server': ''