Avoid creating a page_range into every subcontext
Avoid creating a page_range into every subcontext

so that django-debug-toolbar doesn't have to render lots of stuff for no reason.
Relates to changes in 573cefd2fb27a64cb99d2ab9f14a53f6cdf905c6 and 1de10272a41549fee2e75037f6d7cd6d9752e3ca
jannon/django-haystackbrowser,jannon/django-haystackbrowser,vmarkovtsev/django-haystackbrowser,jannon/django-haystackbrowser,vmarkovtsev/django-haystackbrowser,vmarkovtsev/django-haystackbrowser