organize module alias for debug module

lib/crowi/index.js

@@ -1,7 +1,7 @@
 'use strict';
 
 
-var debug = require('@alias/debug')('crowi:crowi')
+var debug = require('debug')('crowi:crowi')
   , pkg = require('@root/package.json')
   , path = require('path')
   , sep = path.sep

package.json

@@ -177,7 +177,7 @@
   "_moduleAliases": {
     "@root": ".",
     "@alias/logger": "lib/service/logger",
-    "@alias/debug": "lib/service/logger/alias-for-debug"
+    "debug": "lib/service/logger/alias-for-debug"
   },
   "engines": {
     "node": ">=6.11 <9",