message: refactor(compiler): remove 'head' tag contains 'html' tag condition code
  remove 'head' tag contains 'html' tag condition I am not sure this is necessary, but all test passed
  after remove the code.
diff: @@ -222,7 +222,7 @@ export function parseHTML (html, options) {
  }
  }
  - const unary = isUnaryTag(tagName) || tagName === 'html' && lastTag === 'head' || !!unarySlash
  + const unary = isUnaryTag(tagName) || !!unarySlash
  const l = match.attrs.length
  const attrs = new Array(l)
  