fix bug in waitForElementById function

package.json

 {
   "name": "html-custom-elements",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "",
   "main": "index.js",
   "scripts": {

src/html-custom-element.js

@@ -34,7 +34,7 @@ export class HTMLCustomElement extends HTMLElement {
           window.clearInterval(timer);
           resolve(elem);
         }
-      }, 50);
+      }, 50, id);
     });
     return prom;
   }