update thumbnailUrl format

src/main/java/cn/reghao/dfs/store/service/media/ImageFileService.java

@@ -50,7 +50,7 @@ public class ImageFileService {
         ImageFile imageFile = new ImageFile(imageFileId, fileId, horizontal, width, height, url);
         imageFileMapper.save(imageFile);
 
-        String thumbnailUrl = String.format("%s@%s\\w_%s\\h", url, resolution.getWidth(), resolution.getHeight());
+        String thumbnailUrl = String.format("%s@%sw_%sh", url, resolution.getWidth(), resolution.getHeight());
         return new ImageFileRet(uploadedFile.getUploadId(), imageFileId, thumbnailUrl, url);
     }