lfs: fix interpolation of int and %s in an exception case

Seen in the wild in a server log when MS antivirus was quarantining a file on
the client side.

hgext/lfs/blobstore.py

@@ -170,7 +170,7 b' class local:'
             # the localstore, because it's not going to match the expected.
             if content_length is not None and int(content_length) != size:
                 msg = (
-                    b"Response length (%s) does not match Content-Length "
+                    b"Response length (%d) does not match Content-Length "
                     b"header (%d): likely server-side crash"
                 )
                 raise LfsRemoteError(_(msg) % (size, int(content_length)))