Unwrap value in isObservableArray

This will allow the extender to work on a computed observable as well.

Author: marcovdb

knockout-paging.js

@@ -23,7 +23,7 @@
 
   // Utilities
   function isObservableArray(value) {
-    return ko.isObservable(value) && 'push' in value;
+    return ko.isObservable(value) && 'push' in ko.unwrap(value);
   }
 
   function createRange(min, max) {
@@ -234,4 +234,4 @@
   ko.pagedObservableArray = function (initialValue, options) {
     return ko.observableArray(initialValue).extend({ paged: options });    
   };
-}));
+}));