Upgrade bazlets to latest stable-2.15 to build with 2.15.13 API

Change-Id: Ia3e0f53d2834bb30b044b1d073020b587095eabb

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 98e151e..7b45c54 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "8386b3fbf80e375f0a10c8386c0a8dfe260c5c1b",
+    commit = "1650318289e9981c01e9122c62679b814c7d7a48",
     #local_path = "/home/<user>/projects/bazlets",
 )