fix `make new` error (#5111)

build/bin/new.js

@@ -119,7 +119,7 @@ Files.forEach(file => {
 const navConfigFile = require('../../examples/nav.config.json');
 
 Object.keys(navConfigFile).forEach(lang => {
-  let groups = navConfigFile[lang][2].groups;
+  let groups = navConfigFile[lang][3].groups;
   groups[groups.length - 1].list.push({
     path: `/${componentname}`,
     title: lang === 'zh-CN' && componentname !== chineseName