message: refactor: remove unnecessary judgment
diff: @@ -248,12 +248,9 @@ export function parseHTML (html, options) {
  if (start == null) start = index
  if (end == null) end = index
  - if (tagName) {
  - lowerCasedTagName = tagName.toLowerCase()
  - }
  -
  // Find the closest opened tag of the same type
  if (tagName) {
  + lowerCasedTagName = tagName.toLowerCase()
  for (pos = stack.length - 1; pos >= 0; pos--) {
  if (stack[pos].lowerCasedTag === lowerCasedTagName) {
  break
  