Fix the alreadyHighlighted issue

Author: cyrilf

npm-package/CodeEditor.vue

@@ -216,13 +216,15 @@ export default {
     highlight: {
       mounted(el, binding) {
         el.textContent = binding.value;
+        el.removeAttribute('data-highlighted');
         hljs.highlightElement(el);
       },
       updated(el, binding) {
         if (el.scrolling) {
           el.scrolling = false;
         } else {
           el.textContent = binding.value;
+          el.removeAttribute('data-highlighted');
           hljs.highlightElement(el);
         }
       },