don't pass in options from window in handlebars translation
don't pass in options from window in handlebars translation

if you have a handlebars template call with nothing passed in,
it sets "this" to the window, which can cause security problems
in firefox

test plan:
* create a discussion topic with an embedded video (like youtube)
* in firefox, visit the topic and click on "Reply"
* in the rce editor, click on the equation editor button
* should render

(there are other issues with the equation editor that i'll
 handle separately)

closes #CNVS-18194

Change-Id: I584c3ac117a529d691a26497dca5b1327c186989
Reviewed-on: https://gerrit.instructure.com/49598
Tested-by: Jenkins
Reviewed-by: Jeremy Stanley <b3f594e10a9edcf5413cf1190121d45078c62290@instructure.com>
QA-Review: Jahnavi Yetukuri <ed2b2672ccc2e59e56c0615df7f01b579202e014@instructure.com>
Product-Review: James Williams  <3a5f4ed991dbfa5c9ef76ad729d240ca12f62180@instructure.com>

juoni/canvas-lms,samuels410/greatlakes-lms,jay3126/canvas-lms,HotChalk/canvas-lms,Jyaasa/canvas-lms,shidao-fm/canvas-lms,sfu/canvas-lms,venturehive/canvas-lms,HotChalk/canvas-lms,snehakachroo1/LSI_replica,skmezanul/canvas-lms,samuels410/greatlakes-lms,ShreniiNepal/shrenii_lmp,matematikk-mooc/canvas-lms,venturehive/canvas-lms,narigone/canvas,skmezanul/canvas-lms,efrj/canvas-lms,fronteerio/canvas-lms,narigone/canvas,tgroshon/canvas-lms,instructure/canvas-lms,djbender/canvas-lms,Rvor/canvas-lms,sdeleon28/canvas-lms,shidao-fm/canvas-lms,efrj/canvas-lms,leftplusrightllc/canvas-lms,redconfetti/canvas-lms,AndranikMarkosyan/lms,va7map/canvas-lms,narigone/canvas,whalejasmine/canvas-lms,tgroshon/canvas-lms,va7map/canvas-lms,antoniuslin/canvas-lms,eCNAP/CANVAS,ShreniiNepal/shrenii_lmp,dgynn/canvas-lms,snehakachroo1/LSI_replica,utkarshx/canvas-lms,instructure/canvas-lms,antoniuslin/canvas-lms,tgroshon/canvas-lms,sfu/canvas-lms,eCNAP/CANVAS,jay3126/canvas-lms,matematikk-mooc/canvas-lms,tgroshon/canvas-lms,Rvor/canvas-lms,AndranikMarkosyan/lms,ShreniiNepal/shrenii_lmp,greyhwndz/canvas-lms,utkarshx/canvas-lms,skmezanul/canvas-lms,djbender/canvas-lms,narigone/canvas,antoniuslin/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,roxolan/canvas-lms,wrdsb/canvas-lms,Jyaasa/canvas-lms,roxolan/canvas-lms,sfu/canvas-lms,instructure/canvas-lms,AndranikMarkosyan/lms,instructure/canvas-lms,roxolan/canvas-lms,matematikk-mooc/canvas-lms,Rvor/canvas-lms,va7map/canvas-lms,whalejasmine/canvas-lms,shidao-fm/canvas-lms,HotChalk/canvas-lms,wrdsb/canvas-lms,utkarshx/canvas-lms,efrj/canvas-lms,sdeleon28/canvas-lms,grahamb/canvas-lms,grahamb/canvas-lms,whalejasmine/canvas-lms,dgynn/canvas-lms,grahamb/canvas-lms,dgynn/canvas-lms,redconfetti/canvas-lms,leftplusrightllc/canvas-lms,SwinburneOnline/canvas-lms,fronteerio/canvas-lms,leftplusrightllc/canvas-lms,efrj/canvas-lms,juoni/canvas-lms,matematikk-mooc/canvas-lms,HotChalk/canvas-lms,jay3126/canvas-lms,grahamb/canvas-lms,utkarshx/canvas-lms,wrdsb/canvas-lms,dgynn/canvas-lms,greyhwndz/canvas-lms,samuels410/greatlakes-lms,snehakachroo1/LSI_replica,djbender/canvas-lms,djbender/canvas-lms,skmezanul/canvas-lms,greyhwndz/canvas-lms,venturehive/canvas-lms,eCNAP/CANVAS,shidao-fm/canvas-lms,eCNAP/CANVAS,Rvor/canvas-lms,greyhwndz/canvas-lms,fronteerio/canvas-lms,SwinburneOnline/canvas-lms,sfu/canvas-lms,sdeleon28/canvas-lms,juoni/canvas-lms,AndranikMarkosyan/lms,redconfetti/canvas-lms,instructure/canvas-lms,roxolan/canvas-lms,Jyaasa/canvas-lms,fronteerio/canvas-lms,kyroskoh/canvas-lms,instructure/canvas-lms,whalejasmine/canvas-lms,redconfetti/canvas-lms,va7map/canvas-lms,grahamb/canvas-lms,sdeleon28/canvas-lms,antoniuslin/canvas-lms,leftplusrightllc/canvas-lms,Jyaasa/canvas-lms,instructure/canvas-lms,kyroskoh/canvas-lms,wrdsb/canvas-lms,SwinburneOnline/canvas-lms,kyroskoh/canvas-lms,juoni/canvas-lms,SwinburneOnline/canvas-lms,samuels410/greatlakes-lms,ShreniiNepal/shrenii_lmp,kyroskoh/canvas-lms,sfu/canvas-lms,jay3126/canvas-lms,sfu/canvas-lms,snehakachroo1/LSI_replica