Added the media types that the DELETE methods of a resource can accept.

Change-Id: Icf570d086829df51cc4107b3f6efef3efa9e9d21
diff --git a/apps/openstacknetworking/web/src/main/java/org/onosproject/openstacknetworking/web/OpenstackSubnetWebResource.java b/apps/openstacknetworking/web/src/main/java/org/onosproject/openstacknetworking/web/OpenstackSubnetWebResource.java
index d87021d..ca9f3ab 100644
--- a/apps/openstacknetworking/web/src/main/java/org/onosproject/openstacknetworking/web/OpenstackSubnetWebResource.java
+++ b/apps/openstacknetworking/web/src/main/java/org/onosproject/openstacknetworking/web/OpenstackSubnetWebResource.java
@@ -57,6 +57,7 @@
 
     @DELETE
     @Path("{subnetId}")
+    @Produces(MediaType.APPLICATION_JSON)
     public Response deleteSubnet(@PathParam("subnetId") String id) {
         return Response.noContent().build();
     }