Simple xfwm4 patch

[Olivier Fourdan]

Hi Benny,

Benedikt Meurer wrote:

> Attached is a patch for xfwm4 to fix an uninitialized variable which
> would otherwise crash xfwm4 in getUTF8StringList().

Humm, actually this is prolly the bug I've been hunting since yesterday. 
Although the fix belongs to getUTF8StringList() rather than the caller 
in settings.c, this is definitely helpful.

Thanks
Olivier.