clean code

lib/plugins/index.js

@@ -1,8 +1,7 @@
+const debug = require('debug')('crowi:plugins');
 const PluginService = require('./plugin.service');
 
 module.exports = function(crowi, app) {
-  var debug = require('debug')('crowi:plugins');
-
   const pluginService = new PluginService(crowi, app);
   pluginService.loadPlugins();
 }