Update git submodules

* Update plugins/cookbook-plugin from branch 'master'
  - Remove unused imports
    
    Change-Id: I448a2f2567fff0b0bdc81d04e20759fd1c5aafa5
    
diff --git a/plugins/cookbook-plugin b/plugins/cookbook-plugin
index 2dd17f3..7a943fc 160000
--- a/plugins/cookbook-plugin
+++ b/plugins/cookbook-plugin
@@ -1 +1 @@
-Subproject commit 2dd17f35997e5c9bdea4d64acef6db0e42a26242
+Subproject commit 7a943fc5b1052068842c13793754cf161b45e370