erase reply if parent exists fixes #11819
erase reply if parent exists fixes #11819

test plan:
1. delete a root entry
2. load the page (it should work)

Change-Id: I7a6a27bf8253955f74c518981ade3f5b87fee972
Reviewed-on: https://gerrit.instructure.com/15332
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Ryan Shaw <ea3cd978650417470535f3a4725b6b5042a6ab59@instructure.com>

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