update pin to bazel toolchains repo (#216)

diff --git a/WORKSPACE b/WORKSPACE
index 01cdb1c..cb5a744 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -64,11 +64,11 @@
 
 http_archive(
     name = "bazel_toolchains",
-    sha256 = "4b1468b254a572dbe134cc1fd7c6eab1618a72acd339749ea343bd8f55c3b7eb",
-    strip_prefix = "bazel-toolchains-d665ccfa3e9c90fa789671bf4ef5f7c19c5715c4",
+    sha256 = "5962fe677a43226c409316fcb321d668fc4b7fa97cb1f9ef45e7dc2676097b26",
+    strip_prefix = "bazel-toolchains-be10bee3010494721f08a0fccd7f57411a1e773e",
     urls = [
-      "https://mirror.bazel.build/github.com/bazelbuild/bazel-toolchains/archive/d665ccfa3e9c90fa789671bf4ef5f7c19c5715c4.tar.gz",
-      "https://github.com/bazelbuild/bazel-toolchains/archive/d665ccfa3e9c90fa789671bf4ef5f7c19c5715c4.tar.gz",
+      "https://mirror.bazel.build/github.com/bazelbuild/bazel-toolchains/archive/be10bee3010494721f08a0fccd7f57411a1e773e.tar.gz",
+      "https://github.com/bazelbuild/bazel-toolchains/archive/be10bee3010494721f08a0fccd7f57411a1e773e.tar.gz",
     ],
 )