Fix comment on DefaultNamespaceTypeWrapper

Author: paulirwin

src/Lucene.Net.TestFramework/Support/Util/DefaultNamespaceTypeWrapper.cs

@@ -97,7 +97,7 @@ public Assembly Assembly
         /// </summary>
         public string Namespace
         {
-            get { return null; } // LUCENENET: Force this type to be the
+            get { return null; } // LUCENENET: Force this type to be the default
         }
 
         /// <summary>