Update bazlets to latest stable-2.15 to use 2.15rc3

Change-Id: Id3a10415a0639b1a321d58ba3d0330cc82de153e
diff --git a/WORKSPACE b/WORKSPACE
index c8cbd68..3629f3c 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "cbddbc2b9571b1d692fb823ba8791ccd60b52421",
+    commit = "34d5ef186f73c80e61dcfa057ee400b2725164bf",
     # local_path = "/home/<user>/projects/bazlets",
 )