force cuty_capt to send 'Accept-Language:en'
force cuty_capt to send 'Accept-Language:en'

the default accept language header that cuty capt sends does not play nicely
with canvas' locale selection.  so for now, force it to send 'en'.  in the
future it would be nice to have it send the user's configured locale, if it
exists.

fixes CNVS-8421

test plan:
- on a machine with the fix applied, and with cuty capt enabled
- submit a url assignment that points to a canvas installation
  * note: the submitted url does not need the fix applied, just the requester
- the screenshot should be in english

Change-Id: I56a534d4d1eaed92c2615ea500b5960708e49112
Reviewed-on: https://gerrit.instructure.com/24716
QA-Review: Amber Taniuchi <ef4bfd1e6d278f6bc7d4a478f02be2cb9581a0a5@instructure.com>
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Cameron Sutter <853bcc0cb8f5834b7805e8eb9a762054be43c731@instructure.com>
Product-Review: Simon Williams <088e16a1019277b15d58faf0541e11910eb756f6@instructure.com>

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