Remove language="JavaScript"
Pointed out by mah at
bug 209 comment 14. The attribute is and always
has been ignored by browsers, and it also makes validators complain.
The correct thing to use is Html::inlineScript(), which will also omit
the equally useless (but required by XHTML 1) type="text/javascript",
but I didn't do that here because maybe someone is using the extension
with old MediaWiki versions, and it makes no real difference.