lfs: improve an exception message for blob corruption detected on transfer

The message about the server crash originated in 0ee0a3f6a990 (after support for
serving blobs was added), but was copied from the Facebook repo that forked
prior to server side support.  Therefore, this message only displayed in their
client, so it was safe to assume the server crashed.  But that was never the
case for vanilla Mercurial, as I saw this in a server log.

Also, display the blob reference so that it's easier to figure out where the
problem was when a bunch of blobs are transferred at once.

hgext/lfs/blobstore.py

@@ -168,12 +168,16 b' class local:'
             # producing the response (but the server has no way of telling us
             # that), and we really don't need to try to write the response to
             # the localstore, because it's not going to match the expected.
+            # The server also uses this method to store data uploaded by the
+            # client, so if this happens on the server side, it's possible
+            # that the client crashed or an antivirus interfered with the
+            # upload.
             if content_length is not None and int(content_length) != size:
                 msg = (
                     b"Response length (%d) does not match Content-Length "
-                    b"header (%d): likely server-side crash"
+                    b"header (%d) for %s"
                 )
-                raise LfsRemoteError(_(msg) % (size, int(content_length)))
+                raise LfsRemoteError(_(msg) % (size, int(content_length), oid))
 
             realoid = hex(sha256.digest())
             if realoid != oid: