Update git submodules

* Update plugins/replication from branch 'stable-2.15'
  to 404e5069adbdf7d9ab17b887894842ad3638042d
  - Destination: Suppress FutureReturnValueIgnored warning
    
    When all error prone warnings are enabled the FutureReturnValueIgnored
    bug pattern is reported, for example:
    
      plugins/replication/src/main/java/com/googlesource/gerrit/plugins/replication/Destination.java:367:
      error: [FutureReturnValueIgnored] Return value of methods returning Future must be checked.
      Ignoring returned Futures suppresses exceptions thrown from the code that completes the Future.
            pool.schedule(e, now ? 0 : config.getDelay(), TimeUnit.SECONDS);
                         ^
        (see https://errorprone.info/bugpattern/FutureReturnValueIgnored)
      Did you mean to remove this line?
    
    Change-Id: I43b5c3c9f9bf8cda5f2d4ee701b2153e7e6f2807
    
diff --git a/plugins/replication b/plugins/replication
index 20bc91d..404e506 160000
--- a/plugins/replication
+++ b/plugins/replication
@@ -1 +1 @@
-Subproject commit 20bc91d0bd11dd2c9b77aedb6bebb02fa67f70f4
+Subproject commit 404e5069adbdf7d9ab17b887894842ad3638042d