fix: call to wp instead of r for css

The intention of using r was to fix problems with windows paths, but calling r will try to resolve path as well. This was breaking original webpack resolve mechanism from node_modules

lib/app/App.vue

@@ -8,7 +8,7 @@
 <script>
 <% if (loading) { %>import NuxtLoading from '<%= (typeof loading === "string" ? loading : "./components/nuxt-loading.vue") %>'<% } %>
 <% css.forEach(function (c) { %>
-import '<%= r(c.src || c) %>'
+import '<%= wp(c.src || c) %>'
 <% }) %>
 
 let layouts = {

lib/build.js

@@ -10,7 +10,7 @@ import PostCompilePlugin from 'post-compile-webpack-plugin'
 import serialize from 'serialize-javascript'
 import { createBundleRenderer } from 'vue-server-renderer'
 import { join, resolve, basename, dirname } from 'path'
-import { isUrl, r } from './utils'
+import { isUrl, r, wp } from './utils'
 import clientWebpackConfig from './webpack/client.config.js'
 import serverWebpackConfig from './webpack/server.config.js'
 const debug = require('debug')('nuxt:build')
@@ -275,7 +275,8 @@ async function generateRoutesAndFiles () {
       imports: {
         serialize,
         hash,
-        r
+        r,
+        wp
       }
     })
     const content = template(Object.assign({}, templateVars, {

lib/utils.js

@@ -77,7 +77,7 @@ export function chainFn (base, fn) {
   }
 }
 
-function wp (p) {
+export function wp (p) {
   /* istanbul ignore if */
   if (/^win/.test(process.platform)) {
     p = p.replace(/\\/g, '\\\\')