awful.widget.graph and progressbar both create an imagebox. The default is
resize = true which means the image is scaled up inside the wibox if
:set_height() is used.
Setting widget.resize = false avoids this.
Signed-off-by: Uli Schlachter <psychon@znc.in>
Signed-off-by: Julien Danjou <julien@danjou.info>