use a "CacheCover" folder for scaled covers

server/ctrlsubsonic/ctrl.go

@@ -25,8 +25,9 @@ const (
 
 type Controller struct {
 	*ctrlbase.Controller
-	CachePath string
-	Jukebox   *jukebox.Jukebox
+	CachePath      string
+	CoverCachePath string
+	Jukebox        *jukebox.Jukebox
 }
 
 type metaResponse struct {

server/ctrlsubsonic/handlers_raw.go

@@ -106,7 +106,7 @@ func (c *Controller) ServeGetCoverArt(w http.ResponseWriter, r *http.Request) *s
 	}
 	size := params.GetOrInt("size", coverDefaultSize)
 	cachePath := path.Join(
-		c.CachePath,
+		c.CoverCachePath,
 		fmt.Sprintf("%s-%d.%s", id.String(), size, coverCacheFormat),
 	)
 	_, err = os.Stat(cachePath)