fix: log error if branding file exists but cannot be loaded

http/static.go

@@ -124,7 +124,10 @@ func getStaticHandlers(store *storage.Storage, server *settings.Server, assetsFs
 		if d.settings.Branding.Files != "" {
 			if strings.HasPrefix(r.URL.Path, "img/") {
 				fPath := filepath.Join(d.settings.Branding.Files, r.URL.Path)
-				if _, err := os.Stat(fPath); err == nil {
+				_, err := os.Stat(fPath)
+				if err != nil && !os.IsNotExist(err) {
+					log.Printf("could not load branding file override: %v", err)
+				} else if err == nil {
 					http.ServeFile(w, r, fPath)
 					return 0, nil
 				}