message: Fix bug in Ajax
diff: downloadVideo: true,
  downloadDanmaku: true,
  useDefaultPlayerMode: true,
  + medalHelper: true,
  about: true,
  forceWide: false,
  latestVersionLink: "https://github.com/the1812/Bilibili-Evolved/raw/preview/bilibili-evolved.preview.user.js",
  {
  const xhr = new XMLHttpRequest();
  xhr.open("GET", url);
  - return send(xhr);
  + return this.send(xhr);
  }
  static getTextWithCredentials(url)
  {
  const xhr = new XMLHttpRequest();
  xhr.open("GET", url);
  xhr.withCredentials = true;
  - return send(xhr);
  + return this.send(xhr);
  }
  static postText(url, body)
  {
  const xhr = new XMLHttpRequest();
  xhr.open("POST", url);
  xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  - return send(xhr, body);
  + return this.send(xhr, body);
  }
  - static postTextWithCredentials(url)
  + static postTextWithCredentials(url, body)
  {
  const xhr = new XMLHttpRequest();
  xhr.open("POST", url);
  xhr.withCredentials = true;
  xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  - return send(xhr, body);
  + return this.send(xhr, body);
  }
  }
  function downloadText(url, load, error) // The old method for compatibility
  