setNodeAttr: remove attribute if value is null

kss.js

 /*
-*  KSS-RPC v0.9-beta
+*  KSS-RPC v0.10-beta
 *
 *  Copyright (c) 2017, joonis new media
 *  Author: Thimo Kraemer <thimo.kraemer@joonis.de>
@@ -61,7 +61,7 @@
  ******************************************************************************************/
 
 var kss = {
-    version: '0.9-beta',
+    version: '0.10-beta',
     _initialized: false,
     _ruleSheets: {},
     _eventBinders: {},
@@ -1804,6 +1804,10 @@ kss.getNodeAttr = function(node, name, recursive) {
 };
 
 kss.setNodeAttr = function(node, name, value) {
+    if (value === null) {
+        node.removeAttribute(name);
+        return;
+    }
     switch (name) {
         case 'checked':
         case 'selected':