iclouddrive: fix panic and files potentially downloaded twice

- Fixing SIGSEGV Fixes #8211
- Removed files potentially downloaded twice

backend/iclouddrive/api/drive.go

@@ -252,18 +252,14 @@ func (d *DriveService) DownloadFile(ctx context.Context, url string, opt []fs.Op
 	}
 
 	resp, err := d.icloud.srv.Call(ctx, opts)
-	if err != nil {
 	// icloud has some weird http codes
-		if resp.StatusCode == 330 {
+	if err != nil && resp != nil && resp.StatusCode == 330 {
 		loc, err := resp.Location()
 		if err == nil {
 			return d.DownloadFile(ctx, loc.String(), opt)
 		}
 	}
-
 	return resp, err
-	}
-	return d.icloud.srv.Call(ctx, opts)
 }
 
 // MoveItemToTrashByItemID moves an item to the trash based on the item ID.