Add descriptive message for MessagingExceptions.

We can print this message in EventuallyConsistentMapImpl rather than printing
a stack trace which doesn't add any value because the exception always comes
from the same place.

Change-Id: Ia233e7ae8605b2b59ffd4ef834209fdaa86e9376
diff --git a/core/store/dist/src/main/java/org/onosproject/store/cluster/messaging/impl/NettyMessagingManager.java b/core/store/dist/src/main/java/org/onosproject/store/cluster/messaging/impl/NettyMessagingManager.java
index e9b50c4..2e8682b 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/cluster/messaging/impl/NettyMessagingManager.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/cluster/messaging/impl/NettyMessagingManager.java
@@ -545,7 +545,7 @@
                     } else if (message.status() == Status.ERROR_HANDLER_EXCEPTION) {
                         callback.completeExceptionally(new MessagingException.RemoteHandlerFailure());
                     } else if (message.status() == Status.PROTOCOL_EXCEPTION) {
-                        callback.completeExceptionally(new MessagingException.ProcotolException());
+                        callback.completeExceptionally(new MessagingException.ProtocolException());
                     }
                 } else {
                     log.debug("Received a reply for message id:[{}]. "