Update git submodules

* Update plugins/replication from branch 'stable-2.15'
  to 624ec820682e0d7b163e1de262134b7b94087441
  - Allow to configure timeout for SSH connection and commands
    
    The timeout for SSH command execution is hard-coded to 0 which means
    no timeout, and the timeout for SSH connections is hard-coded to 2
    minutes.
    
    Introduce new configuration options to allow configuring each timeout
    individually:
    
      gerrit.sshCommandTimeout
      gerrit.sshConnectionTimeout
    
    When not set, both default to their previously hard-coded values,
    i.e. no limit and 2 minutes respectively.
    
    Change-Id: Ibd377d45543ef4631082e8d521aeeb99209003f7
    Signed-off-by: Dariusz Luksza <dluksza@collab.net>
    Signed-off-by: David Pursehouse <dpursehouse@collab.net>
    
diff --git a/plugins/replication b/plugins/replication
index 95dc833..624ec82 160000
--- a/plugins/replication
+++ b/plugins/replication
@@ -1 +1 @@
-Subproject commit 95dc833b63a1629608c64e343ab07fa6cafc84a9
+Subproject commit 624ec820682e0d7b163e1de262134b7b94087441