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

Change-Id: I4206220e348d22445889c31eb26bceaad7b83df9

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index b5e816f..593964f 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",
 )