Upgrade bazlets to latest stable-2.16 to build with 2.16.19 API

Change-Id: I0e74deb1d2e4153c1b874e0a56b1ef1414a43040
diff --git a/WORKSPACE b/WORKSPACE
index 361ec38..80e1f97 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "855968156ecd58d422218d6b5c9872805df9e9fc",
+    commit = "22b242638bd36017790d94ffcc18a57f223bda2f",
     #local_path = "/home/<user>/projects/bazlets"
 )