wrong width and height for the tracking pixel (“1px” instead of “1”)

In the file plugin’s file \rendering\impression_generator.php the get_html_element_for_pixel_image function return an img html tag such as:

<img src="' . $image_url . '" width="1px" height="1px" alt="" style="position: fixed !important; bottom: -1px !important; right: -1px !important; border:none !important; margin:0px !important;" />

But as far as I know width and height must be expressed as absolute units, in pixels. No need to use “px” in it, as it may invalidate them.