Fix class$ bindings for ShadyDOM.noPatch mode

Author: dfreedm

lib/mixins/properties-changed.js

@@ -497,12 +497,12 @@ export const PropertiesChanged = dedupingMixin(
      */
     _valueToNodeAttribute(node, value, attribute) {
       const str = this._serializeValue(value);
+      if (attribute === 'class' || attribute === 'name' || attribute === 'slot') {
+        node = /** @type {?Element} */(wrap(node));
+      }
       if (str === undefined) {
         node.removeAttribute(attribute);
       } else {
-        if (attribute === 'class' || attribute === 'name' || attribute === 'slot') {
-          node = /** @type {?Element} */(wrap(node));
-        }
         node.setAttribute(attribute, str);
       }
     }