ONOS-4512 vtn-web can't delete router/net/floating/port

Change-Id: I6860aed0c719d4c8f62f21055e650f9f7b29a6f8
diff --git a/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/RouterWebResource.java b/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/RouterWebResource.java
index a4b3fa3..d7389b7 100644
--- a/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/RouterWebResource.java
+++ b/apps/vtn/vtnweb/src/main/java/org/onosproject/vtnweb/resources/RouterWebResource.java
@@ -158,8 +158,10 @@
         }
     }
 
-    @Path("{routerUUID}")
     @DELETE
+    @Path("{routerUUID}")
+    @Consumes(MediaType.APPLICATION_JSON)
+    @Produces(MediaType.APPLICATION_JSON)
     public Response deleteSingleRouter(@PathParam("routerUUID") String id)
             throws IOException {
         try {