[fix] fix insert function

[daybrush]

Fixes #6444

Before submitting the PR, please make sure you do the following

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with npm test and lint the project with npm run lint

[benmccann]

It'd be easier to review and make a cleaner git history if you sent the formatting changes as a separate PR

[daybrush]

@benmccann

I'm sorry. editorconfig worked automatically.

Only one line changed here.

286cd1f#diff-7ad300a4efc821b2576200a7bfc99205d558792b81c037fbc20f9236f8b6f1bbR135

- } else if (node.parentNode !== target || (anchor && node.nextSibling !== anchor)) {
+ } else if (node.parentNode !== target || node.nextSibling !== anchor) {

[daybrush]

@benmccann

Revert formatting?