Upgrade bazlets to latest stable-2.14 to build with 2.14.21 API

Change-Id: I8ccd5c0c93cffdbd6a392f501b0dbeaf296ec90f

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 3162ced..5d340e8 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "b07aa8462f2618a83f3b52d6150faa831b24d3e3",
+    commit = "78c35a7eb33ee5ea0980923e246c7dba37347193",
     #local_path = "/home/<user>/projects/bazlets"
 )