the port is unneccesory forqos flow's action, in fact , config port into qos actionwill cause a bug

Change-Id: I24c2ff9c2b4feda96176e75cd563978ca72be140
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/DecodeInstructionCodecHelper.java b/core/common/src/main/java/org/onosproject/codec/impl/DecodeInstructionCodecHelper.java
index 525033c..2917afd 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/DecodeInstructionCodecHelper.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/DecodeInstructionCodecHelper.java
@@ -365,7 +365,12 @@
         } else if (type.equals(Instruction.Type.QUEUE.name())) {
             long queueId = nullIsIllegal(json.get(InstructionCodec.QUEUE_ID),
                     InstructionCodec.QUEUE_ID + InstructionCodec.MISSING_MEMBER_MESSAGE).asLong();
-            return Instructions.setQueue(queueId, getPortNumber(json));
+            if (json.get(InstructionCodec.PORT) == null ||
+                    json.get(InstructionCodec.PORT).isNull()) {
+                return Instructions.setQueue(queueId, null);
+            } else {
+                return Instructions.setQueue(queueId, getPortNumber(json));
+            }
         } else if (type.equals(Instruction.Type.L0MODIFICATION.name())) {
             return decodeL0();
         } else if (type.equals(Instruction.Type.L1MODIFICATION.name())) {