[Be-shell-general] Conky fix: black background

[Thomas L. <bag...@gm...>]

This commit
https://sourceforge.net/p/be-shell/code/ci/44d790800734749eaba1e539eb31cb21616b2681/
should resolve the issue.

Reason why it worked for me: using native graphicssystem - it only failed  
on the raster graphicssystem.


Cheers,
Thomas