Fixed copy-paste error in NoopPropertyVisitor

(cherry picked from commit 231c9e3)

Author: russcam

src/Nest/Mapping/Visitor/NoopPropertyVisitor.cs

@@ -104,7 +104,7 @@ public void Visit(IProperty type, PropertyInfo propertyInfo, ElasticsearchProper
 
 			var keywordType = type as IKeywordProperty;
 			if (keywordType != null)
-				Visit(textType, propertyInfo, attribute);
+				Visit(keywordType, propertyInfo, attribute);
 
 			var attachmentType = type as IAttachmentProperty;
 			if (attachmentType != null)