修复bug

server.js

@@ -178,7 +178,9 @@ router.post('/reviews', ctx => {
     if (STATIC_DATA.indexOf(el) !== -1) {
       return true
     }
-    noExist.push(el)
+    if (el) {
+      noExist.push(el)
+    }
     return false
   })
   try {