Update git submodules

* Update plugins/replication from branch 'stable-2.16'
  to 757521bc5af9fa050c630bdb7693a1a5bf85d6ef
  - Convert PushResultProcessing to an interface
    
    Instead of being an abstract class with methods that must be explicitly
    overridden (even if they are no-op), convert it to an interface with
    default empty methods. Also introduce a NO_OP instance. This allows to
    have implementations that do nothing without having to explicitly add
    all the boilerplate overrides.
    
    Change-Id: I8a3cf6fc66f9a3857e5fa4949ca99c2c473702d6
    
diff --git a/plugins/replication b/plugins/replication
index 0ee047a..757521b 160000
--- a/plugins/replication
+++ b/plugins/replication
@@ -1 +1 @@
-Subproject commit 0ee047a7d73cb10010ff4923764851982cb38e98
+Subproject commit 757521bc5af9fa050c630bdb7693a1a5bf85d6ef