fix data-pushstate links (like on discussions page)
fix data-pushstate links (like on discussions page)

this function was executing with the wrong “this”,
It needs to be the “this” of the event, not the “global this” (aka)

Test plan:
* In a course, create a discussion.

* Create enough posts so a second page is developed. 
  (Looks like it took me 50 posts on my first page to create a 
  second page)
* use the pagination links to go between pages
* they should work

Change-Id: I7557478a91b0da044076229a373d4ee08b9483f6
Reviewed-on: https://gerrit.instructure.com/193167
Reviewed-by: Landon Gilbert-Bland <60d9ff23682c863d36b48b4c32c5ce5f434d29c0@instructure.com>
QA-Review: Landon Gilbert-Bland <60d9ff23682c863d36b48b4c32c5ce5f434d29c0@instructure.com>
Tested-by: Rob Orton <7e09c9d3e96378bf549fc283fd6e1e5b7014cc33@instructure.com>
Product-Review: Rob Orton <7e09c9d3e96378bf549fc283fd6e1e5b7014cc33@instructure.com>

sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,djbender/canvas-lms,instructure/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,instructure/canvas-lms