[Fontconfig] no `stable' cache file in `~/.fonts'

[Werner LEMBERG]

> In that version, we've tried to prevent the race on updating caches
> by re-scanning a directory after updating a cache once. which isn't
> being done on the latest anymore.

OK, thanks.  Will update.

[I noticed the issue mainly because I have `NotoCJKSans.ttc' (file
 size 112MByte) in the `~/.fonts' directory, and it takes a loong time
 until the many different faces in the TTC are scanned.]


    Werner