Update git submodules
Update git submodules

* Update plugins/replication from branch 'stable-2.15'
  to 1850413298125a857b61d31510ccb22c0dfafc1e
  - ReplicationQueue: Check nulls in firePendingEvents
    
    After a sudden reboot (for unknown reason) Gerrit at startup couldn't
    load because of NullPointerException. There is a possibility that
    stored event was null at that point. Extra logging added to handle null
    events.
    
    Change-Id: I72f34d8def6e0246196cd865f33f6e795b21664b
    
  - Log stack trace when an error occur while deleting event
    
    This will help figuring out root cause of failure to delete event file.
    
    Change-Id: I2f9774c3daf19a04f6b04414ba8145c99bb6e0fe
    (cherry picked from commit b62f006b1350180de0af02c82fb18fb290a2548f)
    
  - Append LF to the json string of persisted replication event
    
    Change-Id: I83ed3f37071125018bf23f6dcd137ef819ef3559
    (cherry picked from commit 5e91925cfd391898e8e33fd149b9e1a115dafee4)
    
  - Change default for the replicateOnStartup to false
    
    Now that replication events are persistent and non-finished replications
    rescheduled after plugin restart the replicateOnStartup feature becomes
    less important. We can change the default value for this option to
    false.
    
    Change-Id: I237d8d8514e01b8786b7db9f39bead4eb475a0a4
    (cherry picked from commit 807790f7d4058235a19b2a766e84628168b64ae6)
    
  - Don't lose ref-updated events on plugin restart
    
    When a ref-updated event is received, persist the event in the directory
    defined by the replication.eventsDirectory. When the updated ref is
    replicated deleted the persisted event.
    
    If replication queue is non-empty and plugin gets stopped, ref updates
    will not be replicated and, therefore, the persisted events will not get
    deleted. When the plugin starts it will schedule replication for all
    persisted events and delete them.
    
    This change provides two benefits:
    * no ref-updated events are lost on plugin restart
    * eliminate need for the replicateOnStartup=true setting which schedules
      replication of all refs for all projects and typically creates a humongous
      replication queue on every plugin restart.
    
    Change-Id: Ieacd084fabe703333241ffda11c8b6c78cced37a
    (cherry picked from commit bdaea910694dd5a3474dbc051b298aaee9d77950)
    
GerritCodeReview/gerrit,qtproject/qtqa-gerrit,WANdisco/gerrit,qtproject/qtqa-gerrit,WANdisco/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,WANdisco/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit