Grunt express livereload and proxy does not work?

Question

I want to launch a web server from grunt with livereload and that proxies Rest calls towards the server. Here is my Gruntfile.js :

 var proxySnippet = require('grunt-connect-proxy/lib/utils').proxyRequest;

module.exports = function(grunt) {
    // Load Grunt tasks declared in the package.json file
    require('matchdep').filterDev('grunt-*').forEach(grunt.loadNpmTasks);
    // 1. Toutes les configurations vont ici:
    grunt.initConfig({
        pkg : grunt.file.readJSON('package.json'),
    watch: {
        all: {
            files: 'webapp/*',
            options: {
                livereload: true,
             }
        },
    },


    express : {
        all : {
            options : {
                bases : 'webapp',
                port : 3000,
                debug:true,
                hostname : "0.0.0.0",
                livereload : true,
                middleware: function (connect, options) {
                    return [proxySnippet];
                }
            },
        }
    },      

    connect: {
        proxies: [{
                context: '/sis.cata/rest',
                host: 'localhost',
                port: 8080,
        https: false,
        changeOrigin: false,
        xforward: false
                }],
    },

    grunt.registerTask('develop', ['configureProxies:connect', 'express:all', 'watch' ]);};

Static files are served but calls to REST services are not proxied and blocks.

Any ideas ?

I have seen solutions with connect and proxy that works fine but never with livereload.

Thanks a lot.