fix bug in #92

[IDKiro]

修复 #92 中提到的bug： 使用监听，在 musicList 更新时对 shuffledList 进行一次更新，从而解决列表切换后的实际播放列表未更换的问题。

[IDKiro]

debug 时使用的 App.vue 测试代码：

<template>
  <div id="app">
    <aplayer
      autoplay
      theme="pic"
      shuffle
      repeat="list"
      show-lrc
      :muted.sync="muted"
      :volume.sync="volume"
      :music='list[0]'
      :list='list'
    />
    <button @click="addList">添加列表</button>
    <button @click="removeList">移除列表</button>
  </div>
</template>
<script>
  import Aplayer from '../vue-aplayer.vue'

  export default {
    name: 'App',
    components: {
      Aplayer,
    },
    data () {
      return {
        version: VERSION,
        volume: 1,
        muted: false,
        music3: null,
        list: [{
            title: '回レ！雪月花',
            artist: '小倉唯',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/snowmoonflowers.mp3',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/snowmoonflowers.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/snowmoonflowers.lrc',
          },
          {
            title: 'あっちゅ～ま青春!',
            artist: '七森中☆ごらく部',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/yuruyuri.mp3',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/yuruyuri.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/yuruyuri.lrc',
          },],
      }
    },
    methods: {
      addList () {
        this.list = [{
            title: '前前前世',
            artist: 'RADWIMPS',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/yourname.mp3',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/yourname.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/yourname.lrc',
          },
          {
            title: '光るなら.m3u8',
            artist: 'Goose house',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/hls/hikarunara.m3u8',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/hikarunara.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/hikarunara.lrc',
          },
          {
            title: '回レ！雪月花',
            artist: '小倉唯',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/snowmoonflowers.mp3',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/snowmoonflowers.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/snowmoonflowers.lrc',
          },
          {
            title: 'あっちゅ～ま青春!',
            artist: '七森中☆ごらく部',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/yuruyuri.mp3',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/yuruyuri.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/yuruyuri.lrc',
          },]
      },
      removeList () {
        this.list = [{
            title: '光るなら.m3u8',
            artist: 'Goose house',
            src: 'https://moeplayer.b0.upaiyun.com/aplayer/hls/hikarunara.m3u8',
            pic: 'https://moeplayer.b0.upaiyun.com/aplayer/hikarunara.jpg',
            lrc: 'https://moeplayer.b0.upaiyun.com/aplayer/hikarunara.lrc',
          }]
      }
    }
  }
</script>
<style>
</style>

另外，如果初始的数组长度为 1（大于 1 时正常），那么不能进行播放。