我正在尝试通过heroku部署MEAN应用程序，但我遇到了困难

Question

我遇到的错误被拒绝加载图像https://xxx.herokuapp.com/favicon.ico，因为它违反了以下内容安全策略指令：“ default-src'none'”。我收到404错误。

我的package.json

{
  "name": "entnepal"`,
  "version": "0.0.0",
  "scripts": {
    "ng": "ng",
    "start": "node Api/server.js",
    "build": "ng build --prod",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "postinstall": "ng build --prod"
  },

我的server.js

const express = require('express'),
    path = require('path'),
    bodyParser = require('body-parser'),
    cors = require('cors'),
    mongoose = require('mongoose');
    config = require('./DB');
    const infoRoute = require('./routes/info.route');
    mongoose.Promise = global.Promise;
    mongoose.connect(config.DB, { useNewUrlParser: true }).then(
      () => {console.log('Database is connected') },
      err => { console.log('Can not connect to the database'+ err)}
    );



const app = express();
app.use(express.static(__dirname + "build")); 
app.get("*", (req, res) => {
  res.sendFile(path.resolve(__dirname, "build", "index.html")); 
});
    app.use(bodyParser.json());
    app.use(cors());
    app.use('/appointment', infoRoute);
    const port = process.env.PORT || 4000;

Procfile
web: node Api/server.js