Update git submodules

* Update plugins/webhooks from branch 'master'
  to 570dacacc64f7c01e0bc0f1301aa1d5a218cfc1b
  - Bazel: Remove unused java_library import
    
    Change-Id: I27e3ea944b55296058ba41cd184078b26f854225
    
diff --git a/plugins/webhooks b/plugins/webhooks
index 377fec1..570daca 160000
--- a/plugins/webhooks
+++ b/plugins/webhooks
@@ -1 +1 @@
-Subproject commit 377fec17d2c0fc71cdfb1d12f502cfa1eba1fbd7
+Subproject commit 570dacacc64f7c01e0bc0f1301aa1d5a218cfc1b