Upgrade bazlets to latest stable-2.16 to build with 2.16.17 API

Change-Id: I9415fd05a9031e1977840c729641209158db4fcb

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index ed820be..6d33a6a 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "2ad931eb07d5a43c7a26132716a1411a47fcbfdf",
+    commit = "9e23df10840ca3976431c842fdada58c7a51c6e3",
     #local_path = "/home/<user>/projects/bazlets",
 )