Kaltura: display error message for actionscript exception
Kaltura: display error message for actionscript exception

fixes CNVS-7015

test plan:
  * open the media comments dialog, such as through conversation composing
  * don't have kaltura set up properly
  * switch to the "Upload Media" tab
  * verify that you get a useful error message
  * verify that the message shows up in IE
  * if possible, verify that you do not get the error message
      if kaltura is set up properly

Change-Id: Ib47633fab427258b35552de9a4ab6f4cb019d217
Reviewed-on: https://gerrit.instructure.com/22526
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Zach Pendleton <514dbb4d54d4f29e454990df7d075678f43f92aa@instructure.com>
QA-Review: Cam Theriault <b4133c36b6d893d0872cc09e87b536d16aa2d241@instructure.com>
Product-Review: Zach Pendleton <514dbb4d54d4f29e454990df7d075678f43f92aa@instructure.com>

loganrun/pincan,arrivu/jigsaw-lms,whalejasmine/canvas-lms,ShreniiNepal/shrenii_lmp,fronteerio/canvas-lms,venturehive/canvas-lms,SwinburneOnline/canvas-lms,wye0220/shindig-canvas,gbleydon/canvas-lms,instructure/canvas-lms,AndranikMarkosyan/lms,matematikk-mooc/canvas-lms,sfu/canvas-lms,usmschuck/canvas,whalejasmine/canvas-lms,loganrun/pincan,matematikk-mooc/canvas-lms,wrdsb/canvas-lms,instructure/canvas-lms,efrj/canvas-lms,narigone/canvas,shidao-fm/canvas-lms,djbender/canvas-lms,HotChalk/canvas-lms,eCNAP/CANVAS,samuels410/greatlakes-lms,va7map/canvas-lms,snehakachroo1/LSI_replica,dgynn/canvas-lms,snehakachroo1/LSI_replica,usmschuck/canvas,sfu/canvas-lms,antoniuslin/canvas-lms,samuels410/greatlakes-lms,shidao-fm/canvas-lms,usmschuck/canvas,merichar/canvas-lms,djbender/canvas-lms,Jyaasa/canvas-lms,skmezanul/canvas-lms,merichar/canvas-lms,utkarshx/canvas-lms,wimemx/Canvas,Rvor/canvas-lms,sfu/canvas-lms,narigone/canvas,juoni/canvas-lms,shidao-fm/canvas-lms,sdeleon28/canvas-lms,fronteerio/canvas-lms,SwinburneOnline/canvas-lms,instructure/canvas-lms,AndranikMarkosyan/lms,greyhwndz/canvas-lms,eCNAP/CANVAS,Unow/canvas-lms,instructure/canvas-lms,wrdsb/canvas-lms,arrivu/arrivu-lms,arrivu/hoodemo,eCNAP/CANVAS,whalejasmine/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,arrivu/hoodemo,wye0220/shindig-canvas,matematikk-mooc/canvas-lms,va7map/canvas-lms,roxolan/canvas-lms,redconfetti/canvas-lms,wimemx/Canvas,narigone/canvas,utkarshx/canvas-lms,jay3126/canvas-lms,arrivu/jigsaw-lms,grahamb/canvas-lms,Rvor/canvas-lms,kyroskoh/canvas-lms,wimemx/Canvas,grahamb/canvas-lms,arrivu/arrivu-lms,matematikk-mooc/canvas-lms,landonwilkins/canvas-lms,ShreniiNepal/shrenii_lmp,Unow/canvas-lms,Rvor/canvas-lms,wye0220/shindig-canvas,sfu/canvas-lms,landonwilkins/canvas-lms,tgroshon/canvas-lms,HotChalk/canvas-lms,utkarshx/canvas-lms,snehakachroo1/LSI_replica,juoni/canvas-lms,kyroskoh/canvas-lms,arrivu/jigsaw-lms,gbleydon/canvas-lms,dgynn/canvas-lms,shidao-fm/canvas-lms,kyroskoh/canvas-lms,redconfetti/canvas-lms,tgroshon/canvas-lms,sdeleon28/canvas-lms,fronteerio/canvas-lms,AndranikMarkosyan/lms,va7map/canvas-lms,usmschuck/canvas,tgroshon/canvas-lms,venturehive/canvas-lms,utkarshx/canvas-lms,antoniuslin/canvas-lms,roxolan/canvas-lms,efrj/canvas-lms,greyhwndz/canvas-lms,venturehive/canvas-lms,wrdsb/canvas-lms,fronteerio/canvas-lms,skmezanul/canvas-lms,samuels410/greatlakes-lms,landonwilkins/canvas-lms,kyroskoh/canvas-lms,snehakachroo1/LSI_replica,tgroshon/canvas-lms,SwinburneOnline/canvas-lms,roxolan/canvas-lms,sfu/canvas-lms,greyhwndz/canvas-lms,leftplusrightllc/canvas-lms,samuels410/greatlakes-lms,merichar/canvas-lms,efrj/canvas-lms,whalejasmine/canvas-lms,Rvor/canvas-lms,HotChalk/canvas-lms,HotChalk/canvas-lms,va7map/canvas-lms,dgynn/canvas-lms,ShreniiNepal/shrenii_lmp,landonwilkins/canvas-lms,leftplusrightllc/canvas-lms,jay3126/canvas-lms,grahamb/canvas-lms,arrivu/qibla-ecampus,grahamb/canvas-lms,djbender/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,Jyaasa/canvas-lms,arrivu/hoodemo,SwinburneOnline/canvas-lms,ShreniiNepal/shrenii_lmp,arrivu/qibla-ecampus,sdeleon28/canvas-lms,jay3126/canvas-lms,jay3126/canvas-lms,juoni/canvas-lms,antoniuslin/canvas-lms,AndranikMarkosyan/lms,arrivu/qibla-ecampus,djbender/canvas-lms,Jyaasa/canvas-lms,greyhwndz/canvas-lms,instructure/canvas-lms,narigone/canvas,roxolan/canvas-lms,antoniuslin/canvas-lms,sdeleon28/canvas-lms,eCNAP/CANVAS,leftplusrightllc/canvas-lms,wrdsb/canvas-lms,Unow/canvas-lms,efrj/canvas-lms,skmezanul/canvas-lms,Jyaasa/canvas-lms,dgynn/canvas-lms,grahamb/canvas-lms,arrivu/arrivu-lms,gbleydon/canvas-lms,venturehive/canvas-lms,loganrun/pincan,leftplusrightllc/canvas-lms,juoni/canvas-lms,redconfetti/canvas-lms,redconfetti/canvas-lms,skmezanul/canvas-lms