Missing number of total paginated pages

[ma00]

Describe the bug

I'm getting "Page 1 of {{ items.paginator.num_pages }}" instead of "Page 1 of 3"

Steps to reproduce

1. Go to a rendered page of article_index_page.html ,
2. Scroll down to the bottom.
3. See error where you find links "next/previous" page

Additional context

Wagtail version 1.0