Update git submodules

* Update plugins/replication from branch 'master'
  to ab6af46f5d191c10a163f4d8a77b75e920bde372
  - Merge branch 'stable-3.1'
    
    * stable-3.1:
      Do not remove replication tasks if they are retrying
    
    Change-Id: I5cbdcd29541f6d88fe93364cc4769b93123138b5
    
  - Do not remove replication tasks if they are retrying
    
    Prevent the premature removal of replication tasks when they
    are scheduled for retry. The termination of a PushOp does not
    necessarily mean that the operation was successful or was definitely
    cancelled: there is also the possibility of retrying upon failures.
    
    Fix an issue where the replication task storage was attempting
    to remove the persistent task and, luckily, failing because the
    task was put back into the waiting queue.
    
    Bug: Issue 12073
    Change-Id: I4751f427aa1c45a8a36232d74e0a6691f860e490
    
diff --git a/plugins/replication b/plugins/replication
index 42a2306..ab6af46 160000
--- a/plugins/replication
+++ b/plugins/replication
@@ -1 +1 @@
-Subproject commit 42a2306d9b746f97f436f9c75982a6dc2b4d84d3
+Subproject commit ab6af46f5d191c10a163f4d8a77b75e920bde372