Upgrade bazlets to latest stable-2.16 to build with 2.16.22 API

Change-Id: I3cc9472371c61265ea2e8a0d22ee3b0cb564d554
diff --git a/WORKSPACE b/WORKSPACE
index 0b29ef8..d680fd1 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "56c9f4ed6dbe3c88f793851c88389637f3714a5d",
+    commit = "8ad33887665f4f6adf7cb465a03f6bd81b95e01d",
     #local_path = "/home/<user>/projects/bazlets"
 )