Replace deprecated JsonObject.readFrom() with Json.parse().asObject

Change-Id: I9e6e5a83edfd2c6abc694c1cc1e939b0b826e980
diff --git a/apps/vtn/vtnweb/src/test/java/org/onosproject/vtnweb/resources/PortPairGroupResourceTest.java b/apps/vtn/vtnweb/src/test/java/org/onosproject/vtnweb/resources/PortPairGroupResourceTest.java
index c13f214..70335ba 100644
--- a/apps/vtn/vtnweb/src/test/java/org/onosproject/vtnweb/resources/PortPairGroupResourceTest.java
+++ b/apps/vtn/vtnweb/src/test/java/org/onosproject/vtnweb/resources/PortPairGroupResourceTest.java
@@ -34,6 +34,7 @@
 
 import javax.ws.rs.core.MediaType;
 
+import com.eclipsesource.json.Json;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -171,7 +172,7 @@
 
         final WebResource rs = resource();
         final String response = rs.path("port_pair_groups/4512d643-24fc-4fae-af4b-321c5e2eb3d1").get(String.class);
-        final JsonObject result = JsonObject.readFrom(response);
+        final JsonObject result = Json.parse(response).asObject();
         assertThat(result, notNullValue());
     }