Remove JCraft JSch dependency

Change-Id: I8e6bec652a6097309d9fbb8d59cf293ec1316f69

src/main/java/com/googlesource/gerrit/plugins/replication/PushOne.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/PushOne.java b/src/main/java/com/googlesource/gerrit/plugins/replication/PushOne.java
index 8b3c9e2..8afcf9b 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/PushOne.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/PushOne.java
@@ -51,7 +51,6 @@
 import com.google.inject.Inject;
 import com.google.inject.assistedinject.Assisted;
 import com.googlesource.gerrit.plugins.replication.ReplicationState.RefPushResult;
-import com.jcraft.jsch.JSchException;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -455,10 +454,7 @@
     } catch (NotSupportedException e) {
       stateLog.error("Cannot replicate to " + uri, e, getStatesAsArray());
     } catch (TransportException e) {
-      Throwable cause = e.getCause();
-      if (cause instanceof JSchException && cause.getMessage().startsWith("UnknownHostKey:")) {
-        repLog.atSevere().log("Cannot replicate to %s: %s", uri, cause.getMessage());
-      } else if (e instanceof UpdateRefFailureException) {
+      if (e instanceof UpdateRefFailureException) {
         updateRefRetryCount++;
         repLog.atSevere().log("Cannot replicate to %s due to a lock or write ref failure", uri);