change computer-template.png

We need a better icon. As temporary workaround, I copied an icon
from the gnome-icon-theme to avoid adding another external source
with different license terms.

www/images/Makefile

@@ -4,6 +4,8 @@ all:
 
 # start.png /usr/share/icons/gnome/16x16/actions/media-playback-start.png
 # stop.png /usr/share/icons/gnome/16x16/actions/media-playback-stop.png
+# computer-template.png /usr/share/icons/gnome/16x16/mimetypes/gnome-mime-application-vnd.sun.xml.calc.template.png
+
 GNOME_IMAGES = 			\
 	start.png		\
 	stop.png		\