Fixing a bug in XosIntegration

Change-Id: I5b4ff467f591fd5e5dd74ea72932704db35d3bf1
diff --git a/apps/xos-integration/src/main/java/org/onosproject/xosintegration/OnosXosIntegrationManager.java b/apps/xos-integration/src/main/java/org/onosproject/xosintegration/OnosXosIntegrationManager.java
index 32f2a68..04dd0b8 100644
--- a/apps/xos-integration/src/main/java/org/onosproject/xosintegration/OnosXosIntegrationManager.java
+++ b/apps/xos-integration/src/main/java/org/onosproject/xosintegration/OnosXosIntegrationManager.java
@@ -279,7 +279,7 @@
             response = builder.post(ClientResponse.class, json);
         } catch (ClientHandlerException e) {
             log.warn("Unable to contact REST server: {}", e.getMessage());
-            return "{ 'error' : 'oops no one home' }";
+            return "{ \"error\" : \"oops no one home\" }";
         }
 
         if (response.getStatus() != HTTP_CREATED) {