Frontmatter Defaults in Components don't override global data

[Severin Klaus]

Let's assume in Global Data:

{ entries: ['a', 'b', 'c'] }

And in component A.pug:

---
entries: null
---

each entry in entries
  p= entry

Now called like this in page.html.haml:

+Component('A')

will output:

<p>a</p><p>b</p><p>c</p>

Expected result:

``