bug 964877 - ensure *app* object has *receipts* property; r=mfinkle

--HG--
extra : rebase_source : 042bf6816913dd5a957f1b17b765a15fbe593698

mobile/android/modules/WebappManager.jsm

@@ -168,7 +168,8 @@ this.WebappManager = {
 
     let message = aData.request || {
       app: {
-        origin: origin
+        origin: origin,
+        receipts: [],
       }
     };