[ONOS-6376] Netconf ssh connection through Apache Mina library

Change-Id: If69fd89afe3082debc3c28a06debfed53426635c
diff --git a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfStreamThread.java b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfStreamThread.java
index 212a4e6..44206e3 100644
--- a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfStreamThread.java
+++ b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfStreamThread.java
@@ -203,7 +203,7 @@
                                      netconfDeviceInfo, deviceReply);
                             NetconfDeviceOutputEvent event = new NetconfDeviceOutputEvent(
                                     NetconfDeviceOutputEvent.Type.DEVICE_UNREGISTERED,
-                                    null, null, Optional.of(-1), netconfDeviceInfo);
+                                    null, null, Optional.of(-2), netconfDeviceInfo);
                             netconfDeviceEventListeners.forEach(
                                     listener -> listener.event(event));
                             this.interrupt();
@@ -256,7 +256,7 @@
             return Optional.of(messageId);
         }
         if (reply.contains(HELLO)) {
-            return Optional.of(0);
+            return Optional.of(-1);
         }
         return Optional.empty();
     }