fix aws style Etag for chunks

weed/server/filer_server_handlers_write_upload.go

@@ -1,6 +1,7 @@
 package weed_server
 
 import (
+	"bytes"
 	"crypto/md5"
 	"hash"
 	"io"
@@ -71,6 +72,11 @@ func (fs *FilerServer) uploadReaderToChunks(w http.ResponseWriter, r *http.Reque
 		if uploadResult.Size == 0 {
 			break
 		}
+		uploadedMd5 := util.Base64Md5ToBytes(uploadResult.ContentMd5)
+		readedMd5 := md5Hash.Sum(nil)
+		if !bytes.Equal(uploadedMd5, readedMd5) {
+			glog.Errorf("md5 %x does not match %x uploaded chunk %s to the volume server", readedMd5, uploadedMd5, uploadResult.Name)
+		}
 
 		// Save to chunk manifest structure
 		fileChunks = append(fileChunks, uploadResult.ToPbFileChunk(fileId, chunkOffset))