Binding broken on <select> within optgroup

[BrianESimon]

2-way binding is broken on <option> elements that are nested within an <optgroup> tag:
https://svelte.technology/repl?version=1.41.2&gist=29dbb2651b80d111672cd74944b4bf57

Instead of "World", the value is set to undefined

[Rich-Harris]

Fixed in 1.41.4. Thanks!