Error when viewing contact that has children that have not configured contact types

[dianabarsan]

To reproduce:

1. Create a place type contact (type doesn't matter). Create 3 persons under this place. (you can also use an existent place that has some contacts).
2. In Fauxton, edit one of these child persons to have a configurable type, but a type that isn't configured.
3. Open the place's contact detail page.
4. Observe the page doesn't load fully:

And there are errors in the console:

On master, the child group appears without a heading (no title to use) and the contacts are listed correctly:

[dianabarsan]

cc @njogz