netty4 OpenFlow southbound

- separate I/O thread and message dispatch threads

Change-Id: I11a10a47de451a9e3063b62f9450be19c3a9dae7
diff --git a/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java b/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java
index fdc1248..9eac361 100644
--- a/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java
+++ b/protocols/openflow/api/src/main/java/org/onosproject/openflow/controller/Dpid.java
@@ -123,7 +123,7 @@
      */
     public static URI uri(long value) {
         try {
-            return new URI(SCHEME, toHex(value), null);
+            return new URI(SCHEME + ":" + toHex(value));
         } catch (URISyntaxException e) {
             return null;
         }