fix ws5 build bustage

xpcom/ds/nsHashtable.h

@@ -125,9 +125,9 @@ public:
   }
   PRBool Put (nsHashKey *aKey,
               nsISupports *aData,
-              nsISupports **value = NULL);
+              nsISupports **value = nsnull);
   nsISupports* Get (nsHashKey *aKey);
-  PRBool Remove (nsHashKey *aKey, nsISupports **value = NULL);
+  PRBool Remove (nsHashKey *aKey, nsISupports **value = nsnull);
   nsHashtable *Clone();
   void Enumerate (EnumFunc aEnumFunc, void* closure = NULL)
   {