When an external app, e.g. kfontinst, installs a font, then kcm rescans its font list. When doing this, only compare urls that are in the current listing scope. i.e. if fonts:/Personal is being rescaned, then only mark/unmark/remove fonts that are within fonts:/Personal.

(Previously in this scenario all fonts within fonts:/System would be removed from the kcm's list (but not actually erased)!)