Upgrade bazlets to latest master to build with 3.2.1 API

Change-Id: I7f48534b1d9169cef2a53c4adff820e5f7bd3686

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 0167f06..c0e98d7 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "5c26af9e0374ede4cd67939be972adf6c4cda791",
+    commit = "53cfe52b1b691040fd03dfe025c0a381df48c6ee",
     #local_path = "/home/<user>/projects/bazlets",
 )