Glimmer rehydration causing title to have <!--%+b:10%-->

Before the render finishes, during the afterModel hook, my DOM looks like this:

```html

<!--%+b:10%-->My Super Project Title<!--%-b:10%-->

```

Which is causing the title of the tab to momentarily be ``

I just upgraded to Ember 2.5.1:

```
DEBUG: -------------------------------
vendor.js:17027 DEBUG: Ember : 3.5.1
vendor.js:17027 DEBUG: Ember Data : 3.5.0
vendor.js:17027 DEBUG: jQuery : 3.3.1
vendor.js:17027 DEBUG: Ember Simple Auth : 1.7.0
vendor.js:17027 DEBUG: -------------------------------
```

The issue seems to be described here: https://github.com/glimmerjs/glimmer-vm/issues/796

The suggested fix is to use triple curlies in the `in-element` component. Which seems bad.