include variable in cache key
include variable in cache key

the only optimization variable affects what will be displayed. it wasn't
in the cache key, so if some view rendered the partial with only ==
'external_urls', then any future renders for the same course (until the
cache expired) would only see the 'external_urls' version, regardless of
their value of only.

Change-Id: I3b9a2e2a7deaab86ffec6d2167d110f82963bce6
Reviewed-on: https://gerrit.instructure.com/7172
Tested-by: Hudson <dfb64870173313a9a7b56f814c8e3b33e268497a@instructure.com>
Reviewed-by: Brian Palmer <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@instructure.com>

venturehive/canvas-lms,ankithbti/canvas_lms,kyroskoh/canvas-lms,juoni/canvas-lms,wimemx/Canvas,sfu/canvas-lms,em2/canvas-lms,arrivu/arrivu-lms,merichar/canvas-lms,arrivu/hoodemo,grahamb/canvas-lms,shidao-fm/canvas-lms,ShreniiNepal/shrenii_lmp,ottenhoff/canvas-lms,venturehive/canvas-lms,whalejasmine/canvas-lms,Rvor/canvas-lms,landonwilkins/canvas-lms,usmschuck/canvas,tgroshon/canvas-lms,landonwilkins/canvas-lms,greyhwndz/canvas-lms,usmschuck/canvas,grahamb/canvas-lms,roxolan/canvas-lms,arrivu/qibla-ecampus,wye0220/shindig-canvas,SwinburneOnline/canvas-lms,usmschuck/canvas,antoniuslin/canvas-lms,rup/Tarrax,kyroskoh/canvas-lms,va7map/canvas-lms,roxolan/canvas-lms,wrdsb/canvas-lms,kyroskoh/canvas-lms,juoni/canvas-lms,va7map/canvas-lms,faraazkhan/canvas,grahamb/canvas-lms,landonwilkins/canvas-lms,leftplusrightllc/canvas-lms,greyhwndz/canvas-lms,wrdsb/canvas-lms,em2/canvas-lms,fronteerio/canvas-lms,Rvor/canvas-lms,sfu/canvas-lms,jay3126/canvas-lms,arrivu/arrivu-lms,leftplusrightllc/canvas-lms,arrivu/hoodemo,redconfetti/canvas-lms,Jyaasa/canvas-lms,utkarshx/canvas-lms,sdeleon28/canvas-lms,sfu/canvas-lms,shidao-fm/canvas-lms,skmezanul/canvas-lms,loganrun/pincan,Unow/ins,ShreniiNepal/shrenii_lmp,shidao-fm/canvas-lms,samuels410/greatlakes-lms,venturehive/canvas-lms,arrivu/hoodemo,tgroshon/canvas-lms,em2/canvas-lms,parbros/red-innovadores-lms,utkarshx/canvas-lms,usmschuck/canvas,merichar/canvas-lms,utkarshx/canvas-lms,efrj/canvas-lms,faraazkhan/canvas,sfu/canvas-lms,skmezanul/canvas-lms,arrivu/jigsaw-lms,djbender/canvas-lms,greyhwndz/canvas-lms,tgroshon/canvas-lms,Unow/canvas-lms,leftplusrightllc/canvas-lms,parbros/red-innovadores-lms,greyhwndz/canvas-lms,djbender/canvas-lms,arrivu/qibla-ecampus,nditech/red-innovadores-lms,ottenhoff/canvas-lms,venturehive/canvas-lms,shidao-fm/canvas-lms,samuels410/greatlakes-lms,utkarshx/canvas-lms,nditech/red-innovadores-lms,loganrun/pincan,wrdsb/canvas-lms,sli7246/canvas_branch,Jyaasa/canvas-lms,sfu/canvas-lms,ankithbti/canvas_lms,wrdsb/canvas-lms,HotChalk/canvas-lms,antoniuslin/canvas-lms,rup/Tarrax,Jyaasa/canvas-lms,skmezanul/canvas-lms,va7map/canvas-lms,redconfetti/canvas-lms,arrivu/qibla-ecampus,HotChalk/canvas-lms,tgroshon/canvas-lms,va7map/canvas-lms,Jyaasa/canvas-lms,redconfetti/canvas-lms,faraazkhan/canvas,sfu/canvas-lms,sdeleon28/canvas-lms,rup/Tarrax,merichar/canvas-lms,whalejasmine/canvas-lms,parbros/red-innovadores-lms,nditech/red-innovadores-lms,efrj/canvas-lms,fronteerio/canvas-lms,HotChalk/canvas-lms,juoni/canvas-lms,Unow/canvas-lms,jay3126/canvas-lms,wye0220/shindig-canvas,arrivu/jigsaw-lms,landonwilkins/canvas-lms,djbender/canvas-lms,sdeleon28/canvas-lms,Unow/ins,efrj/canvas-lms,whalejasmine/canvas-lms,ankithbti/canvas_lms,juoni/canvas-lms,Unow/canvas-lms,sdeleon28/canvas-lms,wimemx/Canvas,leftplusrightllc/canvas-lms,sli7246/canvas_branch,sli7246/canvas_branch,kyroskoh/canvas-lms,Unow/ins,roxolan/canvas-lms,ottenhoff/canvas-lms,roxolan/canvas-lms,skmezanul/canvas-lms,nditech/red-innovadores-lms,ShreniiNepal/shrenii_lmp,loganrun/pincan,ShreniiNepal/shrenii_lmp,arrivu/arrivu-lms,fronteerio/canvas-lms,Rvor/canvas-lms,grahamb/canvas-lms,antoniuslin/canvas-lms,SwinburneOnline/canvas-lms,wye0220/shindig-canvas,wimemx/Canvas,redconfetti/canvas-lms,jay3126/canvas-lms,Rvor/canvas-lms,SwinburneOnline/canvas-lms,SwinburneOnline/canvas-lms,grahamb/canvas-lms,arrivu/jigsaw-lms,whalejasmine/canvas-lms,efrj/canvas-lms,samuels410/greatlakes-lms,sfu/canvas-lms,fronteerio/canvas-lms,HotChalk/canvas-lms,antoniuslin/canvas-lms,samuels410/greatlakes-lms,jay3126/canvas-lms,djbender/canvas-lms