Debug log level where appropriate + Throwing an exception where appropriate

Change-Id: Ica18c122c8a2cb8286d4f48c017a06ffe10452e1
diff --git a/utils/netty/src/main/java/org/onlab/netty/NettyMessagingService.java b/utils/netty/src/main/java/org/onlab/netty/NettyMessagingService.java
index 661e288..f11a513 100644
--- a/utils/netty/src/main/java/org/onlab/netty/NettyMessagingService.java
+++ b/utils/netty/src/main/java/org/onlab/netty/NettyMessagingService.java
@@ -222,7 +222,7 @@
                     try {
                         handler.handle(message);
                     } catch (Exception e) {
-                        log.warn("Failed to process message of type {}", type, e);
+                        log.debug("Failed to process message of type {}", type, e);
                     }
                 });
             }