set some default content for imported topics with no content
set some default content for imported topics with no content

refs #4514

Change-Id: Id1b850b97004950bcae1942226c13654340951fc
Reviewed-on: https://gerrit.instructure.com/3705
Tested-by: Hudson <dfb64870173313a9a7b56f814c8e3b33e268497a@instructure.com>
Reviewed-by: Brian Palmer <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@instructure.com>

gbleydon/canvas-lms,merichar/canvas-lms,utkarshx/canvas-lms,instructure/canvas-lms,grahamb/canvas-lms,nditech/red-innovadores-lms,usmschuck/canvas,matematikk-mooc/canvas-lms,antoniuslin/canvas-lms,redconfetti/canvas-lms,dgynn/canvas-lms,AndranikMarkosyan/lms,snehakachroo1/LSI_replica,roxolan/canvas-lms,utkarshx/canvas-lms,djbender/canvas-lms,landonwilkins/canvas-lms,redconfetti/canvas-lms,juoni/canvas-lms,instructure/canvas-lms,snehakachroo1/LSI_replica,sdeleon28/canvas-lms,narigone/canvas,fronteerio/canvas-lms,Unow/ins,matematikk-mooc/canvas-lms,eCNAP/CANVAS,antoniuslin/canvas-lms,samuels410/greatlakes-lms,faraazkhan/canvas,djbender/canvas-lms,wye0220/shindig-canvas,venturehive/canvas-lms,redconfetti/canvas-lms,va7map/canvas-lms,ottenhoff/canvas-lms,HotChalk/canvas-lms,tgroshon/canvas-lms,fronteerio/canvas-lms,narigone/canvas,em2/canvas-lms,arrivu/jigsaw-lms,narigone/canvas,icelab/canvas,kyroskoh/canvas-lms,juoni/canvas-lms,Rvor/canvas-lms,usmschuck/canvas,icelab/canvas,Jyaasa/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,Rvor/canvas-lms,shidao-fm/canvas-lms,ankithbti/canvas_lms,eCNAP/CANVAS,wrdsb/canvas-lms,kyroskoh/canvas-lms,AndranikMarkosyan/lms,sli7246/canvas_branch,utkarshx/canvas-lms,leftplusrightllc/canvas-lms,arrivu/qibla-ecampus,jay3126/canvas-lms,SwinburneOnline/canvas-lms,kyroskoh/canvas-lms,SwinburneOnline/canvas-lms,arrivu/arrivu-lms,nditech/red-innovadores-lms,fronteerio/canvas-lms,whalejasmine/canvas-lms,arrivu/qibla-ecampus,kyroskoh/canvas-lms,wimemx/Canvas,usmschuck/canvas,antoniuslin/canvas-lms,eCNAP/CANVAS,va7map/canvas-lms,efrj/canvas-lms,leftplusrightllc/canvas-lms,efrj/canvas-lms,skmezanul/canvas-lms,merichar/canvas-lms,arrivu/hoodemo,parbros/red-innovadores-lms,wye0220/shindig-canvas,sli7246/canvas_branch,Unow/canvas-lms,skmezanul/canvas-lms,juoni/canvas-lms,instructure/canvas-lms,sfu/canvas-lms,greyhwndz/canvas-lms,arrivu/arrivu-lms,sfu/canvas-lms,sdeleon28/canvas-lms,rup/Tarrax,gbleydon/canvas-lms,sdeleon28/canvas-lms,snehakachroo1/LSI_replica,Jyaasa/canvas-lms,samuels410/greatlakes-lms,skmezanul/canvas-lms,djbender/canvas-lms,SwinburneOnline/canvas-lms,Unow/ins,ankithbti/canvas_lms,wimemx/Canvas,grahamb/canvas-lms,arrivu/hiring-site,efrj/canvas-lms,nditech/red-innovadores-lms,sli7246/canvas_branch,grahamb/canvas-lms,shidao-fm/canvas-lms,eCNAP/CANVAS,landonwilkins/canvas-lms,grahamb/canvas-lms,antoniuslin/canvas-lms,skmezanul/canvas-lms,SwinburneOnline/canvas-lms,matematikk-mooc/canvas-lms,venturehive/canvas-lms,greyhwndz/canvas-lms,jay3126/canvas-lms,fronteerio/canvas-lms,wrdsb/canvas-lms,HotChalk/canvas-lms,wimemx/Canvas,instructure/canvas-lms,djbender/canvas-lms,roxolan/canvas-lms,HotChalk/canvas-lms,whalejasmine/canvas-lms,instructure/canvas-lms,tgroshon/canvas-lms,snehakachroo1/LSI_replica,juoni/canvas-lms,samuels410/greatlakes-lms,efrj/canvas-lms,nditech/red-innovadores-lms,jay3126/canvas-lms,venturehive/canvas-lms,whalejasmine/canvas-lms,ShreniiNepal/shrenii_lmp,arrivu/qibla-ecampus,ottenhoff/canvas-lms,va7map/canvas-lms,faraazkhan/canvas,roxolan/canvas-lms,arrivu/hiring-site,loganrun/pincan,tgroshon/canvas-lms,Jyaasa/canvas-lms,Jyaasa/canvas-lms,shidao-fm/canvas-lms,utkarshx/canvas-lms,sdeleon28/canvas-lms,arrivu/hoodemo,ShreniiNepal/shrenii_lmp,Unow/canvas-lms,arrivu/hiring-site,sfu/canvas-lms,loganrun/pincan,ankithbti/canvas_lms,rup/Tarrax,greyhwndz/canvas-lms,icelab/canvas,tgroshon/canvas-lms,em2/canvas-lms,redconfetti/canvas-lms,dgynn/canvas-lms,HotChalk/canvas-lms,wrdsb/canvas-lms,whalejasmine/canvas-lms,arrivu/hoodemo,dgynn/canvas-lms,Unow/canvas-lms,wye0220/shindig-canvas,leftplusrightllc/canvas-lms,leftplusrightllc/canvas-lms,AndranikMarkosyan/lms,parbros/red-innovadores-lms,dgynn/canvas-lms,sfu/canvas-lms,Unow/ins,faraazkhan/canvas,narigone/canvas,Rvor/canvas-lms,arrivu/jigsaw-lms,matematikk-mooc/canvas-lms,ShreniiNepal/shrenii_lmp,rup/Tarrax,ottenhoff/canvas-lms,sfu/canvas-lms,AndranikMarkosyan/lms,greyhwndz/canvas-lms,arrivu/arrivu-lms,ShreniiNepal/shrenii_lmp,wrdsb/canvas-lms,usmschuck/canvas,landonwilkins/canvas-lms,va7map/canvas-lms,venturehive/canvas-lms,landonwilkins/canvas-lms,Rvor/canvas-lms,samuels410/greatlakes-lms,roxolan/canvas-lms,jay3126/canvas-lms,instructure/canvas-lms,gbleydon/canvas-lms,loganrun/pincan,grahamb/canvas-lms,em2/canvas-lms,shidao-fm/canvas-lms,arrivu/jigsaw-lms,sfu/canvas-lms,merichar/canvas-lms,parbros/red-innovadores-lms