Bug 12117 - Remove unused image myshadow.png from the staff client

Bug 12117 - Remove unused image myshadow.png from the staff client

myshadow.png was used by a jQuery plugin which has long been removed.
This patch removes it.

To test, search the Koha source for references to myshadow.png.
There should be none.

Followed test plan, patch removed file as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit 5c573a7ad8d50788d3b5a78e58efb8c758a9ec0c)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>