DOCBOOK-APPS: Avoid image scaling for HTML output

[Thomas Singer <thomas dot singer at regnis dot de>]

Hi,

I use the depth parameter of the graphic element to resize my screenshots 
for pdf-output. When I generate HTML output, the image are scaled, too, but 
this looks ugly, because it's done by the browser. I use my own 
transformation stylesheet, that includes html/docbook.xsl. What's the 
easiest way (editing my stylesheet) to generate <img>-tags without the 
height attribute?

Cheers,
Tom