influenced cases:
/testautomation/graphics/optional/d_export_graphic_a.bas
/testautomation/graphics/optional/d_export_graphic_b.bas

1. do not verify exported SVG xml content, just verify
the exported file is existed. Because SVG will be rendered
by Draw directly instead of ASCII import mode (which was
used by the old script to verify the content).

2. replace an inexisted testing picture to an
existed one
Signed-off-by: Jan Holesovsky <kendy@suse.cz>