ONOS-4512 fix bug to get and delete

Change-Id: I952085be7548830b660e133cf1c59fcdf98e8f69
diff --git a/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/ClassifierWebResource.java b/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/ClassifierWebResource.java
index 884ce8c..94534f2 100644
--- a/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/ClassifierWebResource.java
+++ b/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/ClassifierWebResource.java
@@ -18,6 +18,7 @@
 import javax.ws.rs.GET;
 import javax.ws.rs.Path;
 import javax.ws.rs.Produces;
+import javax.ws.rs.Consumes;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 
@@ -45,6 +46,7 @@
      */
     @GET
     @Produces(MediaType.APPLICATION_JSON)
+    @Consumes(MediaType.APPLICATION_JSON)
     public Response getClassifiers() {
 
         ObjectNode result = mapper().createObjectNode();