fix the endless loading in canvas
fix the endless loading in canvas

fixes FALCOR-352

Test Plan
- load more items
- notice it finishes when you are done loading
  items

Change-Id: I48fa4e3b9f696e06bbe472a78429a0ab3636bbc7
Reviewed-on: https://gerrit.instructure.com/115430
Tested-by: Jenkins
Reviewed-by: Clay Diffrient <9dff2e5c98626d20d2848250c411e8009465bb87@instructure.com>
QA-Review: Dan Sasaki <ae19fabf7fe19dff310008c9b6a4d2ec84d311d8@instructure.com>
Product-Review: Steven Burnett <a0b450117c5d20a22d5c4d52bb8ae13adee003d8@instructure.com>

instructure/canvas-planner,instructure/canvas-planner,instructure/canvas-planner