Ensure Kaltura settings protocol matches window protocol

flag=none

Test plan
- Have studio running locally and set the kaltura setting
  for the protocol
- Upload a file from your computer to link in the RCE
  and ensure you don't get errors and the file loads

Change-Id: I40c0cfbeac231eefca1de21f4fd86a97f3cc0706
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/310987
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Ed Schiebel <eschiebel@instructure.com>
QA-Review: Ed Schiebel <eschiebel@instructure.com>
Product-Review: Mysti Lilla <mysti@instructure.com>

ui/shared/media-comments/jquery/kaltura_session_loader.js

@@ -52,6 +52,6 @@ export default class KalturaSessionLoader {
   }
 
   kalturaProtocol() {
-    return INST.kalturaSettings.protocol || window.location.protocol
+    return INST.kalturaSettings.protocol + ':' || window.location.protocol
   }
 }