kodi: fix for saving sking settings on shutdown

[stefansaraev]

backport xbmc/xbmc#9696 to Jarvis

this should fix a known issue after kodi moved skin settings out of guisettings.xml (fixed in krypton) but I am unable to build / runtime test it, so please do a quick test before merging

ref: https://forum.libreelec.tv/thread-53.html

[lrusak]

Thanks @stefansaraev ❤️

[kszaq]

For the record, I've been using this fix from Koying in my community builds: koying/SPMC@91a7962 and there have been no complaints about skin settings not saving since including it.

[stefansaraev]

@kszaq yep, yours will work too. it will force saving every time random setting is changed, which may be slow, and could potentionaly be racy (may corrupt your settings at some point, very unikely to happen but still..)

mine is a bit simpler, it only guarantees that saving skin settings is not blocked by other misbehaving addon, or a crash on kodi exit. if kodi crashes meanwhile, settings wont be saved. it is same behaviour as for guisettings.xml but that's another story

[MilhouseVH]

I've successfully built this for RPi/RPi2/Generic. Have tested RPi2 and it works as expected.