Fixed DOCTYPE in MCHTMLCleaner

We should save original DOCTYPE of html.

If you try to fetch content of "iTunes Connect status update message". It replaces original "HTML 4.01 Transitional" to "XHTML 1.0 Transitional". It results in bad rendering of content in UIWebView.
Hi, I prefer to keep the default value to avoid having a messageID = NULL.
Did you try to fix something?