fix edit rubric button. fixes #10479
fix edit rubric button. fixes #10479

on the show rubric page, when a user edited a rubric, saved it,
and then clicked the edit rubric button again, it wasn't opening
the edit form.

test plan:
  * from course outcomes page, click 'manage rubrics' button;
  * create a new rubric;
  * click the 'edit rubric' button and then click the 'update rubric'
    button;
  * without refreshing the page, click 'edit rubric' again and verify
    that the edit form displays as expected.

Change-Id: If65785f09f1a0f5034d67b503597bc674d79f2d5
Reviewed-on: https://gerrit.instructure.com/13688
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Ryan Florence <2d8900489f91ac272fd9ce9d5789db6522668ca2@instructure.com>

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