fix parse cssModules loader query (#729)

Author: guox191

lib/loader.js

@@ -143,7 +143,7 @@ module.exports = function (content) {
     return loader.replace(/((?:^|!)css(?:-loader)?)(\?[^!]*)?/, function (m, $1, $2) {
       // $1: !css-loader
       // $2: ?a=b
-      var query = loaderUtils.getOptions($2 || {}) || {}
+      var query = loaderUtils.parseQuery($2 || '?')
       Object.assign(query, OPTIONS, option, DEFAULT_OPTIONS)
       if (index !== -1) {
         // Note: