fix: safer removeChild by checking parent node

Author: encloinc

src/hmr/hotModuleReplacement.js

@@ -130,7 +130,7 @@ function updateCss(el, url) {
   newEl.isLoaded = false;
 
   newEl.addEventListener("load", () => {
-    if (newEl.isLoaded) {
+    if (newEl.isLoaded || el.parentNode === null) {
       return;
     }
 
@@ -139,7 +139,7 @@ function updateCss(el, url) {
   });
 
   newEl.addEventListener("error", () => {
-    if (newEl.isLoaded) {
+    if (newEl.isLoaded || el.parentNode === null) {
       return;
     }