Wrong order for some nodes unrelated to shadow dom

The expected order of nodes outside of the shadow root was wrong. Since
there is no identical tabindex in use, the order is simply tabindex.
"before any element whose tabindex attribute has a value greater than
the value of the tabindex attribute on the element."
Merge pull request #591 from KenjiBaheux/focus-navigation-fix2

Wrong order for some nodes unrelated to shadow dom