konqueor 3.0.3: not correctly handle charset=gb2312

[Yang Shouxun <yangsx@fltrp.com>]

Konqueror in KDE 3.0.3 does not always display Chinese pages correctly. 
After some efforts, I narrow it down to this.

If the webpage contains a line such as
--->8---
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
--->8---
to specify the charset to be used, konqueror 3.0.3 will not correctly 
display the page. Some Chinese characters are missing, showing just a 
blank space instead.

For an instance, http://www.lingchina.org

When I save the page to hard disk, remove "; charset=gb2312", and reload 
the file in Konqueror, all works file.