title: "gerrit: replicate: not found" even after installing replication plugin
body: <p>I am using gerrit for code review and I use, replication plugin to keep the repo in sync with github.com .</p>
  
  <p>But, the replication is not working. It throws me error:</p>
  
  <pre><code>[2014-01-16 11:23:04,694] ERROR com.googlesource.gerrit.plugins.replication.ReplicationQueue : Cannot replicate to git@github.com:visitvinoth/gerrit_prj_1.git
  org.eclipse.jgit.errors.TransportException: git@github.com:visitvinoth/gerrit_prj_1.git: reject HostKey: github.com
      at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:142)
      at org.eclipse.jgit.transport.SshTransport.getSession(SshTransport.java:121)
      at org.eclipse.jgit.transport.TransportGitSsh$SshFetchConnection.&lt;init&gt;(TransportGitSsh.java:248)
      at org.eclipse.jgit.transport.TransportGitSsh.openFetch(TransportGitSsh.java:147)
      at com.googlesource.gerrit.plugins.replication.PushOne.listRemote(PushOne.java:468)
      at com.googlesource.gerrit.plugins.replication.PushOne.doPushAll(PushOne.java:416)
      at com.googlesource.gerrit.plugins.replication.PushOne.generateUpdates(PushOne.java:409)
      at com.googlesource.gerrit.plugins.replication.PushOne.pushVia(PushOne.java:357)
      at com.googlesource.gerrit.plugins.replication.PushOne.runImpl(PushOne.java:340)
      at com.googlesource.gerrit.plugins.replication.PushOne.runPushOperation(PushOne.java:267)
      at com.googlesource.gerrit.plugins.replication.PushOne.access$000(PushOne.java:78)
      at com.googlesource.gerrit.plugins.replication.PushOne$1.call(PushOne.java:240)
      at com.googlesource.gerrit.plugins.replication.PushOne$1.call(PushOne.java:237)
      at com.google.gerrit.server.util.RequestScopePropagator$5.call(RequestScopePropagator.java:222)
      at com.google.gerrit.server.util.RequestScopePropagator$4.call(RequestScopePropagator.java:201)
      at com.google.gerrit.server.git.PerThreadRequestScope$Propagator$1.call(PerThreadRequestScope.java:75)
      at com.googlesource.gerrit.plugins.replication.PushOne.run(PushOne.java:237)
      at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
      at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
      at java.util.concurrent.FutureTask.run(FutureTask.java:166)
      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)
      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)
      at com.google.gerrit.server.git.WorkQueue$Task.run(WorkQueue.java:360)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
      at java.lang.Thread.run(Thread.java:724)
  Caused by: com.jcraft.jsch.JSchException: reject HostKey: github.com
      at com.jcraft.jsch.Session.checkHost(Session.java:780)
      at com.jcraft.jsch.Session.connect(Session.java:342)
      at org.eclipse.jgit.transport.JschConfigSessionFactory.getSession(JschConfigSessionFactory.java:116)
      ... 25 more
  </code></pre>
  
  <p>I have already registered the RSA key of the gerrit user in github.com on my account.</p>
  
  <p>When I try triggering the replicate command manually, </p>
  
  <pre><code>ssh -p 29412 vinoth@xxx.xxx.xx.xx gerrit replicate gerrit_prj_1
  </code></pre>
  
  <p>I get the error,</p>
  
  <pre><code>gerrit: replicate: not found
  </code></pre>
  
  <p>Please help</p>